PyAPI: make internal modules explicitly "private"

Rename modules in `./scripts/modules/` to use an underscore prefix to
make it clear they aren't intended to be part of public API's. This
also means there is no implication that these modules should be stable,
allowing us to change them based on Blender's internal usage.

The following modules have been marked as private:

- `animsys_refactor`
- `bl_console_utils`
- `bl_i18n_utils`
- `bl_previews_utils`
- `bl_rna_utils`
- `bl_text_utils`
- `bl_ui_utils`
- `bpy_restrict_state`
- `console_python`
- `console_shell`
- `graphviz_export`
- `keyingsets_utils`
- `rna_info`
- `rna_manual_reference`
- `rna_xml`

Note that we could further re-arrange these modules
(under `_bpy_internal` in some cases), this change is mainly to mark
them as private, further changes can be handed on a case-by-case basis.

Ref !147773

scripts/modules/_bl_i18n_utils/utils_cli.py

@@ -0,0 +1,144 @@
+# SPDX-FileCopyrightText: 2020-2023 Blender Authors
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Some useful operations from utils' I18nMessages class exposed as a CLI.
+
+import os
+
+if __package__ is None:
+    import settings as settings_i18n
+    import utils as utils_i18n
+    import utils_languages_menu
+else:
+    from . import settings as settings_i18n
+    from . import utils as utils_i18n
+    from . import utils_languages_menu
+
+
+def update_po(args, settings):
+    pot = utils_i18n.I18nMessages(uid=None, kind='PO', src=args.template, settings=settings)
+    if os.path.isfile(args.dst):
+        uid = os.path.splitext(os.path.basename(args.dst))[0]
+        po = utils_i18n.I18nMessages(uid=uid, kind='PO', src=args.dst, settings=settings)
+        po.update(pot)
+    else:
+        po = pot
+    po.write(kind="PO", dest=args.dst)
+
+
+def cleanup_po(args, settings):
+    uid = os.path.splitext(os.path.basename(args.src))[0]
+    if not args.dst:
+        args.dst = args.src
+    po = utils_i18n.I18nMessages(uid=uid, kind='PO', src=args.src, settings=settings)
+    po.check(fix=True)
+    po.clean_commented()
+    po.write(kind="PO", dest=args.dst)
+
+
+def strip_po(args, settings):
+    uid = os.path.splitext(os.path.basename(args.src))[0]
+    if not args.dst:
+        args.dst = args.src
+    po = utils_i18n.I18nMessages(uid=uid, kind='PO', src=args.src, settings=settings)
+    po.clean_commented()
+    po.write(kind="PO_COMPACT", dest=args.dst)
+
+
+def rtl_process_po(args, settings):
+    uid = os.path.splitext(os.path.basename(args.src))[0]
+    if not args.dst:
+        args.dst = args.src
+    po = utils_i18n.I18nMessages(uid=uid, kind='PO', src=args.src, settings=settings)
+    po.rtl_process()
+    po.write(kind="PO", dest=args.dst)
+
+
+def language_menu(args, settings):
+    # 'DEFAULT' and en_US are always valid, fully-translated "languages"!
+    stats = {"DEFAULT": 1.0, "en_US": 1.0}
+
+    po_to_uid = {
+        os.path.basename(po_path_work): uid
+        for can_use, uid, _num_id, _name, _isocode, po_path_work
+        in utils_i18n.list_po_dir(settings.WORK_DIR, settings)
+        if can_use
+    }
+    for po_dir in os.listdir(settings.WORK_DIR):
+        po_dir = os.path.join(settings.WORK_DIR, po_dir)
+        if not os.path.isdir(po_dir):
+            continue
+        for po_path in os.listdir(po_dir):
+            uid = po_to_uid.get(po_path, None)
+            # print("Checking {:s}, found uid {:s}".format(po_path, uid))
+            po_path = os.path.join(po_dir, po_path)
+            if uid is not None:
+                po = utils_i18n.I18nMessages(uid=uid, kind='PO', src=po_path, settings=settings)
+                stats[uid] = po.nbr_trans_msgs / po.nbr_msgs if po.nbr_msgs > 0 else 0
+    utils_languages_menu.gen_menu_file(stats, settings)
+
+
+def main():
+    import sys
+    import argparse
+
+    parser = argparse.ArgumentParser(description="Tool to perform common actions over PO/MO files.")
+    parser.add_argument(
+        '-s', '--settings', default=None,
+        help="Override (some) default settings. Either a JSON file name, or a JSON string.",
+    )
+    sub_parsers = parser.add_subparsers()
+
+    sub_parser = sub_parsers.add_parser('update_po', help="Update a PO file from a given POT template file")
+    sub_parser.add_argument(
+        '--template', metavar='template.pot', required=True,
+        help="The source pot file to use as template for the update.",
+    )
+    sub_parser.add_argument('--dst', metavar='dst.po', required=True, help="The destination po to update.")
+    sub_parser.set_defaults(func=update_po)
+
+    sub_parser = sub_parsers.add_parser(
+        'cleanup_po',
+        help="Cleanup a PO file (check for and fix some common errors, remove commented messages).",
+    )
+    sub_parser.add_argument('--src', metavar='src.po', required=True, help="The source po file to clean up.")
+    sub_parser.add_argument('--dst', metavar='dst.po', help="The destination po to write to.")
+    sub_parser.set_defaults(func=cleanup_po)
+
+    sub_parser = sub_parsers.add_parser(
+        'strip_po',
+        help="Reduce all non-essential data from given PO file (reduce its size).",
+    )
+    sub_parser.add_argument('--src', metavar='src.po', required=True, help="The source po file to strip.")
+    sub_parser.add_argument('--dst', metavar='dst.po', help="The destination po to write to.")
+    sub_parser.set_defaults(func=strip_po)
+
+    sub_parser = sub_parsers.add_parser(
+        'rtl_process_po',
+        help="Pre-process PO files for RTL languages.",
+    )
+    sub_parser.add_argument('--src', metavar='src.po', required=True, help="The source po file to process.")
+    sub_parser.add_argument('--dst', metavar='dst.po', help="The destination po to write to.")
+    sub_parser.set_defaults(func=rtl_process_po)
+
+    sub_parser = sub_parsers.add_parser(
+        'language_menu',
+        help="Generate the text file used by Blender to create its language menu.",
+    )
+    sub_parser.set_defaults(func=language_menu)
+
+    args = parser.parse_args(sys.argv[1:])
+
+    settings = settings_i18n.I18nSettings()
+    settings.load(args.settings)
+
+    if getattr(args, "template", None) is not None:
+        settings.FILE_NAME_POT = args.template
+
+    args.func(args=args, settings=settings)
+
+
+if __name__ == "__main__":
+    print("\n\n *** Running {} *** \n".format(__file__))
+    main()