Major refactor: split codebase into multiple files

Now for the fun part: will this compile?

Sources/YTMiniPlayerEnabler.x

@@ -0,0 +1,9 @@
+#import "uYouPlus.h"
+
+// YTMiniPlayerEnabler: https://github.com/level3tjg/YTMiniplayerEnabler/
+%hook YTWatchMiniBarViewController
+- (void)updateMiniBarPlayerStateFromRenderer {
+    if (IS_ENABLED(@"ytMiniPlayer_enabled")) {}
+    else { return %orig; }
+}
+%end