Create wrapper around spotify-auth-api and spotify-app-remote

[adamint]

Issue: API instantiation on android is still too confusing and DIY. spotify-web-api-kotlin has gradually expanded its targets, but its JVM beginnings are still evident in the lack of documentation around mobile authentication.

Solution:

1. Two dependencies, to spotify-auth-api and app-remote, will be added for the Android target. iOS target is TBD.
2. Wrapper around authentication APIs will be provided in the style of existing builders (3.6.0)
3. Wrapper around SpotifyAppRemote APIs will be provided in the style of a new API inside SpotifyClientApi (AppRemoteWrapperApi) (3.6.1)
4. Succinct documentation around how to use both wrappers will be provided (3.6.0-3.6.1)
5. Example application for Android will be developed (3.6.2)
6. Samples will be developed and fully cover the library (3.6.3)

Target for 3.6.0 is March 14, 2021.

spotify-auth wrapper is now complete and needs testing.

[RWitak]

Any updates on this would be highly appreciated, I do struggle a lot with the Android Auth process, even with the help of the example app...
But still, thanks for the awesome work so far!

[adamint]

Hi @RWitak, apologies for the absurdly late response. This is as much for anyone coming across this in the near future. Auth integration has already been completed and is documented, but app-remote integration has not been