AclManager: Split callbacks for LE and classic

Multiplex disconnection events and command to LE and classic.
Remove separate disconnect callbacks for classic.
Add macros for buffering callbacks until they are registered.
Remove UnregisterCallbacks() (just disconnect)
Remove Finish() (when disconnect is complete it will get cleaned up)

Bug: 145832107
Test: ./cert/run --host && bluetooth_test_gd
Change-Id: I3c84ae10510c548361e79c3ba0ffdc0506d46e1e