Remove/Clear issues that aren't affecting the app currently.

[KelvnPere]

I noticed that the majority of the issues currently in the issues pane are either old or no longer related to the app. Keeping the issues open doesn't look neat for the repository and just clearing in general looks good and shows the project is being well maintained and cared for.

Below are list of all the issues currently opened and i will be using this issue to keep track of each one of them:

1. Getting invalid error about playing on multiple devices #56
2. Have to hit enter to make search #85
3. Replace FIREBASE_CI_TOKEN with razeware account #105
4. Download Animation feels buggy #134
5. Attempting to playback any video crashes on Android 7.1.1 #210
6. [My Tutorials] Add prompt when first visiting this tab for the first time #212
7. [Collection] Delete/Reset Progress on Completed Collections #219
8. [Filter] There should be more spacing below Flutter (same as above iOS & Swift) #221
9. [Beta] PIP is buggy on Xiaomi devices #224
10. [Beta] Scroll position is not maintained in library screen #227
11. [My tutorials] In progress-Completed screen shows up blank #228
12. [Beta] Captions are not showing occasionally #230
13. My Tutorials doesn't update live #235
14. Text cutoff on login screen #239
15. Space at top of all pages #241
16. Tap lock icons to mark an episode #265
17. Support LastPass, 1Password, etc #277
18. Playback While Locked #278
19. Library Screen Performance #289
20. Global: Light Mode Style Updates #294
21. v1.0.8 Material Design Proguard issue #295
22. Update to v1 API Key #296
23. Downloaded videos are missing subtitles #310
24. Filters: Update Design to match iOS #313
25. Global: Reduce space at top of all screens #314
26. Remove BoundaryCallbackNotifier #322
27. System navigation bar overlaps with buttons #335
28. Theming for arrow back on search field while on light mode #345
29. Unable to login #351
30. Unable to access content #352

Cc @sammyd