Add suffix input and support empty strings in prefix/suffix

[consideRatio]

Adds a suffix input and supports specifying an empty string element in a list of prefixes/suffixes via either prefix or suffix input by specifying "" instead.

Having suffix next to prefix is probably generally useful, but I have a use case for jupyterhub/jupyter-remote-desktop-proxy to publish the same image with the suffixes "" and "-tiger" as planned via jupyterhub/jupyter-remote-desktop-proxy#88.

This is an example of how I'd use it there:

        # ...
        with:
          prefix: |
            quay.io/jupyterhub/jupyter-remote-desktop-proxy:
          suffix: |
            ""
            -tigervnc
          # ...

[consideRatio]

@manics sorry for pinging for review and pushing changes after, I won't touch this further now though.

[manics]

The idea seems fine. Have you thought about using "" to mean the empty string?

[consideRatio]

Have you thought about using "" to mean the empty string?

Yes! I found an issue is that we had a whitespace and/or comma deliminated list for prefix, so doing that would be weird there. I looked to use the same syntax for suffix/prefix, and to not make a breaking change. I also concluded that if i made use of new lines as separators for suffix, it would end up making users write hard-to-write-correctly and hard-to-understand yaml config.

[manics]

I meant (basically) '""' not just "". So

          suffix: |
            ""
            -tigervnc

          suffix: "", -tigervnc

[consideRatio]

Ah, okay - we can do that also! I'll update this PR to reflect that when i'm at a computer next time!

[consideRatio]

@manics done!

[manics]

Code looks good!

The new parameter is missing from the README:
https://github.com/consideRatio/action-major-minor-tag-calculator/tree/pr/add-suffix-input?tab=readme-ov-file#optional-input-parameters

[consideRatio]

Thank you @manics, great catches!

[consideRatio]

Force pushed away repeated auto-format and update dist stuff commits.