Add to IDL API that allows the user to add and remove clauses on a table's condition
iteratively. IDL maintain tables condition and send monitor_cond_change to the server
upon condition change.
Add tests for conditional monitoring to IDL.
Signed-off-by: Liran Schour <lirans@il.ibm.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>