Refactor: make "sys_info" an internal module, rename for clarity

- Move sys_info into an internal module to avoid having so many
  top level modules for Blender's internal functionality.
- Rename system_info sub-modules that pre-fill URL's for clarity.
- Move top-level exception handling into the operator.
- Report an error if an unexpected exception occurs.
- Use `Exception` instead of `BaseException` as there is no reason to
  catch the additional exceptions.
- Remove use of sys_info from the command line example,
  replace with in-lined system info.

doc/python_api/examples/bpy.utils.register_cli_command.py

@@ -5,25 +5,74 @@ Registering commands makes it possible to conveniently expose command line
 functionality via commands passed to (``-c`` / ``--command``).
 """
 
-import sys
 import os
 
 import bpy
 
 
+def sysinfo_print():
+    """
+    Report basic system information.
+    """
+
+    import pprint
+    import platform
+    import textwrap
+
+    width = 80
+    indent = 2
+
+    print("Blender {:s}".format(bpy.app.version_string))
+    print("Running on: {:s}-{:s}".format(platform.platform(), platform.machine()))
+    print("Processors: {!r}".format(os.cpu_count()))
+    print()
+
+    # Dump `bpy.app`.
+    for attr in dir(bpy.app):
+        if attr.startswith("_"):
+            continue
+        # Overly verbose.
+        if attr in {"handlers", "build_cflags", "build_cxxflags"}:
+            continue
+
+        value = getattr(bpy.app, attr)
+        if attr.startswith("build_"):
+            pass
+        elif isinstance(value, tuple):
+            pass
+        else:
+            # Otherwise ignore.
+            continue
+
+        if isinstance(value, bytes):
+            value = value.decode("utf-8", errors="ignore")
+
+        if isinstance(value, str):
+            pass
+        elif isinstance(value, tuple) and hasattr(value, "__dir__"):
+            value = {
+                attr_sub: value_sub
+                for attr_sub in dir(value)
+                # Exclude built-ins.
+                if not attr_sub.startswith(("_", "n_"))
+                # Exclude methods.
+                if not callable(value_sub := getattr(value, attr_sub))
+            }
+            value = pprint.pformat(value, indent=0, width=width)
+        else:
+            value = pprint.pformat(value, indent=0, width=width)
+
+        print("{:s}:\n{:s}\n".format(attr, textwrap.indent(value, " " * indent)))
+
+
 def sysinfo_command(argv):
     import tempfile
-    import sys_info
 
     if argv and argv[0] == "--help":
         print("Print system information & exit!")
         return 0
 
-    with tempfile.TemporaryDirectory() as tempdir:
-        filepath = os.path.join(tempdir, "system_info.txt")
-        sys_info.write_sysinfo(filepath)
-        with open(filepath, "r", encoding="utf-8") as fh:
-            sys.stdout.write(fh.read())
+    sysinfo_print()
     return 0