feat(player): add player text size, end card grid layout, and end car…

[ThushanMadu]

This pull request introduces three new user interface features for the YouTube extension, focusing on improving video player text size, end card layout, and end card title behavior. The changes include both JavaScript logic to enable these features and corresponding CSS for their visual appearance.

New player and end card customization features:

• Added a "Player Text Size" feature that allows toggling between normal and compact text sizes in the video player and related UI elements, with "compact" as the default to address recent YouTube text size increases. [1] [2]
• Introduced an "End Card Grid Layout" feature that restores the classic 3x4 grid layout for video end cards, including responsive adjustments for smaller screens. [1] [2]
• Added an "End Card Title Hover" feature, which hides end card video titles by default and reveals them on hover for a cleaner look. [1] [2]

Integration and initialization:

• Registered the new features (playerTextSize, endCardGridLayout, and endCardTitleHover) in the extension's initialization process to ensure they are applied when the extension loads.…d title hover features

This PR fixes #3217

[ThushanMadu]

@ImprovedTube

[ImprovedTube]

hi! and thank you so much @ThushanMadu

(the JS in general.js is not required, we automated that. )
In our menu files toggles / dropdowns need to be specified with the names used in JS or CSS. And human language messages defined in at least en/messages.json.