Enhancements

[GabrielCalin]

I added some enhancements that are useful for me, maybe they help others too.
IMPORTANT: the code is written with Antigravity and while it works for my use cases (mainly: Smart Playlists), things might be broken in other places / the code might not be ideal - I wanted to have something fast and I didn't know the codebase. But maybe something good can be extracted from here.

• Works with Ampache 7. I got some errors with the original code that are fixed now.
• I added a proxy which takes care of CORS issues in the browser when running locally without having to install a CORS plugin in the browser.
• For me with a Smart Playlist of 700 songs, when I pressed Play at the playlist level, I had to wait over 30 seconds for the first song to start playing. Also, the UI was blocked during this wait time. Now, the code will first start playing the first song, then in a more optimal way, add items to the playing queue.
• I added a new button, Play From Here in the three dots menu of individual songs. I wanted to have a way to add to the queue all songs after one specific song. I listen to playlists in order usually and I want a way to be able to continue from where I stopped.
• Pressing Play at playlist level or Play From Here will take into account current sorting.
• Album is also shown in the playing bar between song name and artist name. This is also helpful for scrobbling to websites such as last.fm via web-scrobbler for example.

I might add a functionality to edit (and maybe bulk edit) song metadata because I really need that possibility.