lfrc - Added 5 new mappings, 3 of which pipe to clipboard

[TheYellowArchitect]

1. Copies the selected filename (Y currently copies filepath, not filename), and pipes it to clipboard.

2. Copies the selected filename and if it matches the yt-dlp downloaded video format [1234567891011], gets the full youtube URL and pipes it to clipboard. For example, the file "API calls in Godot 4 under 4 minutes [hC38DsPUDVk].mkv" pipes the string "https://www.youtube.com/watch?v=hC38DsPUDVk" to the clipboard.

3. Copies the selected filename and if it matches the yt-dlp downloaded video format [1234567891011], gets the full piped.video URL and pipes it to the clipboard. (piped.video is a mirror of youtube, even includes comments) For the same example file as above, it pipes the string "https://piped.video/watch?v=hC38DsPUDVk" to the clipboard.

4. Opens current folder in full picture mode (sxiv). Think windows large icons mode. Good for browsing quickly through image albums. Mapped to T character, which is intuitive (Thumbnails)

5. Ctrl+l to unselect all selections so the behaviour matches the terminal.