bluetooth: host: add checks for connection types

Fail gracefully if an HCI event of one type arrives for a handle of a
different connection type.  The requested types are currently based on
what fields are used, not on the usage context, in order to keep every
correct use so far still working.

A warning is logged if the connection identified by the handle does not
match the requested connection type.

Signed-off-by: Arkadiusz Kozdra <akozdra@antmicro.com>