Upgrade ARD player to 6.3.5

From 6.3.5 upward, the iOS package and module are renamed to ARD-Player (without -iOS).
Also all Events are now uppercase (ARDPlayerEvent and ARDPlayerEvents).

The iOS deployment target is raised to 13.0.
Some fiddling around with modular_headers and flipper in the Podfile of the example application:
Flipper is incompatible and needed to be disabled