profile: dynamic per-share in-memory counters

profile: dynamic per-share in-memory counters

Mechanism to support per-share per-process run-time profiling counters.
Use in-memory cache for storing run-time entries, using 'snum' as key.
When storing in TDB file, uses unique key for each per-share profile
entry.

Signed-off-by: Shachar Sharon <ssharon@redhat.com>
Signed-off-by: Avan Thakkar <athakkar@redhat.com>
Reviewed-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Anoop C S <anoopcs@samba.org>