STASHDEV-7788 Remove the code to timeout remote operations on the remote node

STASHDEV-7788 Remove the code to send CallTimeoutException responses
from remote operation threads back to the caller to indicate timeout.
These are expensive to deserialize (especially when the contents of
the CallTimeoutException are not used for anything anyway), and when
the queue is long can lead to an indefinitely growing queue of retried
invocations.
The bug here seemed to be an implicit assumption that operations implementing `WaitSupport` should be aborted when the call timeout is exceeded.  This isn't true, they were actually retried and/or checked with `IsStillExecutingOperation` before being aborted.