Android Intent handling in Qt 6

The following APIs from QtAndroidExtras are very related to each other:

• QAndroidActivityResultReceiver: for handling the activity result asynchronous.
• QAndroidIntent
• QtAndroid::startActivity(...) and QtAndroid::startIntentSender(...): takes Intent and either QtAndroidActivityResultReceiver or a lambda callback.

We need to figure out what the final place for those API should be. Some of those APIs like QAndroidActivityResultReciever are used by modules like QtNfc which is expected to be brought back in 6.2.

Dependencies to: NFC, BT and Purchasing