api: create_workflow allows illegal characters

[tiborsimko]

CLI does not allow users to enter illegal charaters:

$ reana-client create -w test.41
 ==> ERROR: Workflow name test.41 contains illegal character "."

API does:

>>> my_workflow_name = 'test.42'
...
>>> create_workflow_from_json(
...     workflow_json=my_workflow,
...     name=my_workflow_name,
...     access_token=my_reana_token,
...     parameters=my_inputs,
...     workflow_engine=my_workflow_type)
  -> SUCCESS: Valid REANA specification file.
 ...site-packages/urllib3/connectionpool.py:1013: InsecureRequestWarning: Unverified HTTPS request is being made to host 'localhost'. Adding certificate verification is strongly advised. See: https://urllib3.readthedocs.io/en/1.26.x/advanced-usage.html#ssl-warnings
    warnings.warn(
    {'message': 'Workflow workspace created', 'workflow_id': 'efa63d64-76e5-433d-a207-3cb303ec348a', 'workflow_name': 'test.42.1'}

Note test.42 was accepted and workflow name test.42.1 was created. This causes problems launching workflows, since dots are interpreted as restarts.

We should fix Python API in order not to allow illegal characters, similarly to CLI API.

[matthewfeickert]

Thanks for spotting this @tiborsimko. :+1: