Starting watcher should wait for the watches to be started before
marking the status as started.

Also, reloading watcher could set the execution service to paused. This could
lead to watches not being executed, when run in tests. This fix does not
change the paused flag in the execution service, just clears out the
current queue and executions.

Some tests were affected by this because after putting a watch, the
execution service was still marked as paused, so that the manual
execution with the ScheduleEngineTriggerMock did not work.

Closes elastic#30381

…ion-service-state

…ion-service-state