Move tests/data and assets to the main repository

This change moves the tests data files and publish folder of assets
repository to the main blender.git repository as LFS files.

The goal of this change is to eliminate toil of modifying tests,
cherry-picking changes to LFS branches, adding tests as part of a
PR which brings new features or fixes.

More detailed explanation and conversation can be found in the
design task.

Ref #137215

Pull Request: https://projects.blender.org/blender/blender/pulls/137219

tests/python/modules/io_report.py

@@ -131,7 +131,7 @@ class Report:
             message += """<p><tt>BLENDER_TEST_UPDATE=1 ctest -R %s</tt></p>""" % test_suite_name
             message += """<p>The reference output of new and failing tests will be updated. """ \
                        """Be sure to commit the new reference """ \
-                       """files to the tests/data git submodule afterwards.</p>"""
+                       """files to the tests/files git submodule afterwards.</p>"""
             message += """</div>"""
             message += f"Tested files: {self.tested_count}, <b>failed: {len(self.failed_list)}</b>"
         else:

tests/python/modules/render_report.py

@@ -343,7 +343,7 @@ class Report:
             message += """<p><tt>BLENDER_TEST_UPDATE=1 ctest -R %s</tt></p>""" % self.engine_name
             message += """<p>This then happens for new and failing tests; reference images of """ \
                        """passing test cases will not be updated. Be sure to commit the new reference """ \
-                       """images to the tests/data git submodule afterwards.</p>"""
+                       """images to the tests/files git submodule afterwards.</p>"""
             message += """</div>"""
         else:
             message = ""