Fix slow library loading with a lot of inclusions or exclusions

[Andrius-B]

This closes #534 - the library loads very slowly when there are entries in the blacklist. Seems that I found the issue - there was a hidden O(N^2) loop in the incl/excl filtering algorithm.
I converted the include/exclude path lists to hash sets that have fast member checks and this seems to solve the performance problems:

[(no exclusions) + app start..]
2021-08-24 21:00:50.683 15138-15138/com.simplecity.amp_pro.debug I/PERF: Requested album load
2021-08-24 21:00:51.159 15138-15205/com.simplecity.amp_pro.debug I/PERF: Albums loaded 295 in 476ms
[app restart..]
2021-08-24 21:01:14.905 15356-15356/com.simplecity.amp_pro.debug I/PERF: Requested album load
2021-08-24 21:01:15.357 15356-15434/com.simplecity.amp_pro.debug I/PERF: Albums loaded 295 in 451ms
[blacklist spotify cache folders + app restart..]
2021-08-24 21:02:02.308 15773-15773/com.simplecity.amp_pro.debug I/PERF: Requested album load
2021-08-24 21:02:02.677 15773-15839/com.simplecity.amp_pro.debug I/PERF: Albums loaded 188 in 368ms
[app restart..]
2021-08-24 21:02:24.031 16003-16003/com.simplecity.amp_pro.debug I/PERF: Requested album load
2021-08-24 21:02:24.455 16003-16108/com.simplecity.amp_pro.debug I/PERF: Albums loaded 188 in 423ms

Now if I'm not mistaken, this should now be O(N) and scale a little better.

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