Remove cylc submit and cylc jobscript

[datamel]

This PR also involves rewriting some functional tests as unit tests.

Note, I have not removed all of the functional tests in the jobscript directory. I believe the ones I have left are useful functional tests that test jobscript and are more suited to functional tests than unit tests.

The functional tests removed have been replaced by unit tests, with the exception of tests/jobscript/01-multi.t - this currently relies on cylc jobscript command and is not suited to unit testing. This is testing that namespace_hierarchy is correctly populated and is covered by other tests.

These changes relate to #1249

• I have read CONTRIBUTING.md and added my name as a Code Contributor.
• Contains logically grouped changes (else tidy your branch by rebase).
• Does not contain off-topic changes (use other PRs for other changes).
• Appropriate tests are included (unit and/or functional).
• Appropriate change log entry included.
• I will open a documentation PR at cylc/cylc-doc

[oliver-sanders]

Quick skim, looks good.

[oliver-sanders]

That's a somewhat strange way to test it!

This is effectively a "known good output" test, so we could just include the "good output", that way when the test breaks you get a diff.

[kinow]

Looks good to me. Impressive work @datamel, to go through all these tests, and update some to unit tests! 👏

Later I think we also need to update the cylc-docs? e.g. https://github.com/cylc/cylc-doc/blob/06beda801367437072cc485a9262efda678f991a/src/user-guide/task-job-submission.rst#task-job-submission-and-management & https://github.com/cylc/cylc-doc/blob/06beda801367437072cc485a9262efda678f991a/src/user-guide/task-implementation.rst#task-job-scripts ? (EDIT: just saw your comment in the pull request issue template, ignore that :-) )

[oliver-sanders]

Later I think we also need to update the cylc-docs?

The CLI docs are probably a bit out-of-wack, once we've got the CLI properly implemented we will auto-document the CLI.

[hjoliver]

@kinow 's links above do point at references to cylc jobscript in the User Guide text, so it's not just the "CLI docs" (if by that you mean the the auto-generated command help docs).

[oliver-sanders]

True, though there is something we can do to automate this.

We now write cylc configurations in this syntax:

You can change this with :cylc:conf:`suite.rc[scheduling]max active cycle points`.

If we renamed or removed max active cycle points then the docs would fail to build due to a broken reference. We can do the same thing with commands:

You can see what the job script looks like using the :command:`cylc jobscript` command.