Update Scenario Selector documentation with 4.0 features (#1216)

* - Added Filtering, Sorting and Searching section in the Scenario Selector doc page.
- Added actual MUI icons to be used in the doc body text (added to the table control doc page).
- Tiny doc adjustement in the metric control formatting paragraph.
- Tiny doc change in the toggle control.
- Force UTF-8 encoding in Markdown generation.
- Release Notes updated.
- Copy front-end code for Core elements

tools/fetch_source_files.py

@@ -335,6 +335,8 @@ def copy(item: str, src: str, dst: str, rel_path: str):
                 shutil.copytree(os.path.join(fe_src_dir, "src"), os.path.join(frontend_dir, "src"))
                 for f in [f for f in os.listdir(fe_src_dir) if f.endswith(".md") or f.endswith(".json")]:
                     shutil.copy(os.path.join(fe_src_dir, f), os.path.join(frontend_dir, f))
+                core_fe_src_dir = os.path.join(src_path, "frontend", "taipy")
+                shutil.copytree(os.path.join(core_fe_src_dir, "src"), os.path.join(frontend_dir, "core_src"))
 
                 # Copy INSTALLATION.md, CONTRIBUTING.md, and CODE_OF_CONDUCT.md
                 if not os.path.isdir(taipy_documentation_files_dir):