support PATCH /jobs/{job_id} (modify a batch job)

[soxofaan]

came up in #55 : VITO backend does not support PATCH /jobs/{job_id}:

openeo-python-driver/openeo_driver/views.py

Lines 551 to 555 in eff8fda

	@openeo_bp.route('/jobs/<job_id>', methods=['PATCH'])
	@auth_handler.requires_bearer_auth
	def modify_job(job_id, user: User):
	# TODO
	raise FeatureUnsupportedException()

[m-mohr]

It also doesn't support deleting jobs.