Add field access & modify JVMTI callbacks

This adds support for the FieldAccess and FieldModification callbacks
in JVMTI and all other functions and behaviors associated with the
can_generate_field_modification_events and
can_generate_field_access_events capabilities.

Tests follow in the next CL.

Bug: 34409228
Test: ./test.py --host -j40

Change-Id: Id18fc53677cc1f96e1460c498ade7607219d5a79