refactor: commands to use machinery and clean up unused functions

[CGoodwin90]

Checklist

• Affected Issues have been mentioned in the Closing issues section
• Documentation has been written/updated.
• Changelog entry has been written

This PR introduces some command reorganization, refactors most commands to be in-line with more recent additions & cleans up the legacy functions.

Changes:

• Refactors most commands still using the legacy client to interact with the api to now utilize machinery
• Adds helper functions for error handling and argument validation
• Fixes minor bugs - incorrect alias', invalid return data etc
• Removes unused legacy functions

Note: Some legacy functions remain as they are being used by functionality outside of this PR (e.g. Importer), which will be updated in a seperate PR.

[shreddedbacon]

@CGoodwin90 are you still working on this? Would be cool to look at merging before it gets crazier

[CGoodwin90]

@CGoodwin90 are you still working on this? Would be cool to look at merging before it gets crazier

Nah it's good to go, was just waiting for #332 to go in first. I'll rebase and mark ready.

[shreddedbacon]

This is all good now.

Will need to ensure the release notes contain a notification about the breaking changes to some flags