(maint) Add xbps used by voidlinux as a package provider

[Animeshz]

I wanted to use puppet on void-linux, so this PR adds the package provider for xbps.

Let me know if any changes has to be made :)

[puppetlabs-jenkins]

Can one of the admins verify this patch?

[CLAassistant]

All committers have signed the CLA.

[Animeshz]

@joshcooper @tvpartytonight (just pinging).

Rebased on tip of main branch removing conflicts, can someone please review.

[joshcooper]

Hi @Animeshz thanks for your pull request! I had a few minor comments, but generally looked great.

[Animeshz]

I had a few minor comments, but generally looked great.

I got those addressed (and tested basic functionality on local machine), let me know if anything else has to be done.

[Animeshz]

Sorry I didn't performed lint checks. I've addressed those nuances now.

And tests should now pass. Please have a look 😄

[joshcooper]

closing and reopening to trigger checks

[joshcooper]

@Animeshz can you fix the rubocop checks by running bundle exec rubocop -a and squash your commits?

[Animeshz]

It used to pass all checks that time, seems like rubocop rules have been changed since then.

Let me rebase, fix and squash up real quick.

EDIT: Done, checked rake tests and rubocop suggestions.