Refactor: SSH/SFTP Connections

[lewislarsen]

Vanguard PR

Description

This is a refactor of how Vanguard communicates with Linux servers.

How Has This Been Tested?

• [x] Automated testing (Feature tests, Unit tests)
• [x] Manual testing (explain the steps)

Checklist:

• [x] I have performed a self-review of my own code
• [x] My changes do not introduce any new warnings or errors
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing tests pass locally with my changes

[lewislarsen]

This is currently a WIP with the basic implementation done.

Further testing is needed, and to slowly migrate over parts of the codebase that use the more mock heavy style of connecting to this system.

It should be an improvement and make it much more testable.

This will take a while, but it should be a vast improvement and hopefully in the end I'll be happy with it.

[lewislarsen]

Pretty happy with the progress so far.

It needs to undergo more manual testing, and then I can think about moving the Backup SSH/SFTP connections over to it.

Currently it's being used by any server checking mechanism and the remove SSH key feature.