Add most-recently played song in the "get user profile" endpoint

[aramperes]

Use-Case Description

Add the user's most recently played item in the "Get user profile" endpoint. This should be useful to avoid an extra call in those cases.

This may or may not give the currently playing song if any - TBD.

Semantics

This will be a field containing the song info and play date, same as the "get recently played" endpoint.