allow downloading playlists from popup menu

[Araxeus]

🧿 fix #516 , fix #432, fix #190

Allows downloading playlist from the popup menu (previously the button was shown buy didn't work as intended)

The following is the basic way it works:

global.download = () => { 
    let videoUrl = getSongMenu().....href
    ...
    if (videoUrl.includes('?playlist=')) {
		ipcRenderer.send('download-playlist-request', videoUrl);
		return;
	}
]

it also removes the button when the popup menu is opened from an artist page header's (since there is nothing to download)

youtube-music/plugins/downloader/front.js

Lines 23 to 25 in 21c149e

	if (menuUrl && !menuUrl.includes('watch?')) return;
	menu.prepend(downloadButton);

Note: INVALID_PLAYLIST_MODIFIER = 'RDAMPL' is an invalid modifier that shows up when getting playlist id from the popup-menu of a playlist page (in that case the first button is radio and this modifier is inserted into the id)

🧿 update ytdl-core (many improvements including way faster download speed), fix #492

🧿 fix playback-speed slider showing up on popup menu's it shouldn't show in (c7e793b)

Screenshots of fixed playlist download buttons in the popup menu (Click to reveal)

NOTE: the playback speed slider is showing up when it shouldn't in those screenshots but was also fixed afterwards in c7e793

in playlist page header

in playlist square renderer

in artist page

[th-ch]

Looks good, thanks for the fix! ✅