Add tags to run specific tasks in the playbook

[jtpio]

This mostly applies to the tljh.yml playbook.

We should add tags to be able to select specific tasks to run, and make the upgrade process smoother.

This will also fix https://github.com/plasmabio/plasmabio/issues/53.

[jtpio]

Now that the https and admin setup have been moved to separate playbooks, it looks like tags are not strictly needed anymore.

The tljh.yml playbook mostly does 2 things:

• Update the TLJH plugin Python package (equivalent to pip install -U)
• Run the TLJH installer (still with the --plugin option)

If the TLJH plugin has changed and needs to be updated, the installer should re-run too because the plugin might have updated its hooks. The hooks are processed by the TLJH installer.

So it looks like executing the tljh.yml playbook should be enough (as mentioned in https://docs.plasmabio.org/en/latest/install/upgrade.html#running-the-playbook).

[jtpio]

Linking to the current content of tljh.yml for reference:

https://github.com/plasmabio/plasmabio/blob/c6a53f6d28e8613de2ed0d1cb9ffc87144135c73/ansible/tljh.yml#L8-L47