[split] rcore, web, desktop, android changes (batch 5) (#3345)

* Move SetExitKey from core to android, desktop, web

* Move some callbacks from core to desktop and web

* Relocate emscripten callbacks on web

* Relocate android callbacks on android

* Revert "Relocate android callbacks on android"

This reverts commit bbdbecc.

* Updates UnloadVrStereoConfig on rcore

* Update SetClipboardText on android

* Fix screenMin/Max default values for android