New authentication flow to resolve #515

[jacksongoode]

This resolves the issue with a new OAuth method largely referencing the work done in librespot librespot-org/librespot#1309. After this username/pass is completely depreciated. I may not have removed all unused references so I'd be happy for reviews and edits.

[jacksongoode]

@Insprill Since this is a big one and high prio, would you have time to look over this and review?

[jacksongoode]

@SO9010 Just to check with another person, does this method work for you from this branch?

[kingosticks]

By the way, now everyone required is back from holiday we'll hopefully be merging our librespot PR for this. It's currently going through some review. The intention is to publish a librespot-oauth create but when that'll see an actual release, I can't say. I appreciate you might prefer to control your own copy of that code, this is more just a note that the original version is seeing some updates (error handling mostly) so there may be value in waiting for those.

[SO9010]

@SO9010 Just to check with another person, does this method work for you from this branch?

I'll try it out tomorrow!

[jacksongoode]

By the way, now everyone required is back from holiday we'll hopefully be merging our librespot PR for this. It's currently going through some review. The intention is to publish a librespot-oauth create but when that'll see an actual release, I can't say. I appreciate you might prefer to control your own copy of that code, this is more just a note that the original version is seeing some updates (error handling mostly) so there may be value in waiting for those.

@kingosticks Thanks for the update, I've been following changes to that PR. I think it does just make sense to roll our own implementation here. If you notice anything odd here feel free to point it out, it was based around your work so thank you!

[SO9010]

@jacksongoode This works perfectly for me!!!