osd, messenger, librados: lttng enhancements

osd, messenger, librados: lttng enhancements

Few critical functions have been instrumented with function tracing
and oid tracing calls to help routing performance analysis.
Oid tracing events are heavily dependent on functional changes and may need
to be revised as and when core data flow logic changes.

Signed-off-by: Anjaneya Chagam <anjaneya.chagam@intel.com>