Add support for additional VM tags

[NocDerEchte]

Description

The option for adding tags to the created VMs would help when managing the VMs in PVE and tools like ProxLB could use the added tags to ensure that, for example, control-plane nodes get scheduled on different nodes to ensure high-availability even if one PVE node fails.

There is also an Issue (#51) that requested this feature.

I hope that my additions make sense and the code is somewhat good. My go experience is pretty limited.

If I forgot something to add, feel free to point it out.

Thanks!

PS.: You did a great job building this tool, keep up the good work!

How Has This Been Tested?

• Installed Extension via Rancher
• Deployed test-cluster with added tags

Everything worked and the tags were added to the created VMs. Including the "old" tag "docker-machine".

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[keyaray]

Looks great! I'll test it tomorrow.