Issue
Resolves #6199

Releasing the GIL with pybind

        // release the GIL
         py::gil_scoped_release release;

This seem to work fine, mostly due to this being a relatively simple function, and the data inside it is guarded by the job_node mutex.

Regarding confirmed_running:

We determined that the way the refresh function was refactored, it was reading/checking for the same file over-and-over again needlessly. This way we limit the checking from when the state is JOB_QUEUE_RUNNING and only until the existence of the file is proven.

 if (current_status & JOB_QUEUE_RUNNING && !node->confirmed_running) {
             node->confirmed_running =
                 !node->status_file || fs::exists(node->status_file);

Re-add submit+kill functions that was reverted earlier

A month ago we reverted some functions that was ported from cwrap to pybind, where the experience was a slowdown/lockdown of the whole application.
Using gil_scoped_release we can re-add these functions again, with the same premises as other code in this PR.

Pre review checklist

• Read through the code changes carefully after finishing work
• Make sure tests pass locally (after every commit!)
• Prepare changes in small commits for more convenient review (optional)
• PR title captures the intent of the changes, and is fitting for release notes.
• Updated documentation
• Ensured that unit tests are added for all new behavior (See
  Ground Rules),
  and changes to existing code have good test coverage.

Pre merge checklist

• Added appropriate release note label
• Commit history is consistent and clean, in line with the contribution guidelines.