Add more tests for tags

[ssbarnea]

More tests for #236

[ssbarnea]

@MarkusTeufelberger Next time we need negative tests.

[MarkusTeufelberger]

These might also be worth it:

Playbooks:

- name: Array with members but not string
  hosts: localhost
  tags:
    - 123 # <-- not allowed

Tasks:

- name: Array with members but not string
  ansible.builtin.debug:
    msg: foo
  tags:
    - 123 # <-- not allowed

[ssbarnea]

We can do this after we remove the old schemas via #239 as I do not fancy updating 3 files instead of one.

[MarkusTeufelberger]

...these tests already do not pass (correctly), there would be no change necessary other than adding them.