OTMA client notification of IMS termination

OTMA clients are notified when IMS terminates to prevent them from sending new requests after IMS shuts down.

During a planned IMS shutdown, OTMA sends the protocol commands TMAMMNTR (X'3C' Resource Monitor) and TMAMCSPA (X'14' Suspend TPIPE) to all OTMA clients.

During an unplanned IMS shutdown, OTMA leaves the XCF group during abend processing and XCF exit routines notify the OTMA clients.