Add toggleable content warning bypass (fixes #3591)

[IsVohi]

Problem

Content warning prompts interrupt playlist autoplay, requiring manual clicks on "I understand and wish to proceed".

Solution

Added a toggleable feature that automatically appends &rco=1 parameter to bypass content warnings.

Changes

• Created src/content-scripts/bypass-content-warning.js
• Added toggle in General settings (default: enabled)
• Updated manifest.json with content script registration
• Real-time toggle (no page reload needed)

User Control

Users can disable the feature if they prefer to see content warnings, as requested by issue author.

Testing

• ✅ Videos with content warnings auto-play
• ✅ Normal videos unaffected
• ✅ Playlist autoplay continues through warned videos
• ✅ Toggle on/off works immediately
• ✅ Setting persists across sessions

Closes #3591

[ImprovedTube]

Thank you! @IsVohi

we can easily (potentially automatically) load most features like:

ImprovedTube.storage.bypassYouTubeContentWarning === true {
bypassYoutubeContentWarning(); }
on page load and youtube navigation

so that each feature function can be modular, not require to look up storage again. And only need its individual event listening, if any.