Rewrite test that checks whether task_manager/wait_task works properly.
The old version didn't work. Delete functions used in old version.
Closes#14959
* github.com:scylladb/scylladb:
test: rewrite wait_task test
test: move ThreadWrapper to rest_util.py
When running compaction task test on the same scylla instantion
other tests are run, some compaction tasks from other test cases may
be left in task manager. If they stay in memory long enough, they may
get unregistered during the compaction task test and cause bad_request
status.
Drain old compaction tasks before and after each test.
Fixes: #14584.
Closes#14585
In task manager and task manager test rest apis when a task or module
which does not exist is requested, we get Internal Server Error.
In such cases, wrap thrown exceptions in bad_param_exception
to respond with Bad Request code.
Modify test accordingly.
Task manager api will be used in many tests. Thus, to make it easier
api calls to task manager are wrapped into functions in task_manager_utils.py.
Some helpers that may be reused in other tests are moved there too.
