Update JDWP event filtering to avoid useless ids

To reduce the number of JDWP ids in the debugger, we update the event filtering
support to work with runtime objects (Thread, Class, Object, ...) instead of
JDWP ids (ThreadId, RefTypeId, ObjectId, ...).

We used to create useless JDWP ids for events even if they were not reported
because of event filtering (thread only, class only, instance only, ...). Now
we only create JDWP ids when we know we're going to report an event.

Bug: 17343664
Change-Id: Ib83df6d82fbcb40895f5cd9201a1e9ecd0a07e17