MAJOR: counters: add shared counters base infrastructure

MAJOR: counters: add shared counters base infrastructure

Shareable counters are not tagged as shared counters and are dynamically
allocated in separate memory area as a prerequisite for being stored
in shared memory area. For now, GUID and threads groups are not taken into
account, this is only a first step.

also we ensure all counters are now manipulated using atomic operations,
namely, "last_change" counter is now read from and written to using atomic
ops.

Despite the numerous changes caused by the counters being moved away from
counters struct, no change of behavior should be expected.