MediaTube 2.26.3 - AI Rewrite Text Formatting

New MediaTube Options:
- Title formatting: No formatting / Capitalize Title / CAPITAL LETTERS TITLE
- Description formatting: No formatting / Capitalize Description / CAPITAL LETTERS DESCRIPTION

The formatter is applied after AI rewrite and is UTF-8/multibyte safe.
Because each field uses one select list, Title Case and UPPERCASE cannot be selected at the same time.

Applied to:
- Frontend MP4/MP3/RTMP/embed/provider additions
- Administrator media saves
- Selected-item AI batch rewrite / formatting
