ssh key validation

[sheldor1510]

• ssh key validation done with PublicKeyLoader
• added ajax call for ssh key validation on textarea change
• added red box shadow to textarea and disabled "Add Key" button if key is not valid
• added ssh key validation code on the backend for both cases of paste and file import
• Check ssh key format for 'paste' option.  #17

[hakasapl]

Some minor code cleanup changes, other than that this looks really good, thanks!

[sheldor1510]

@hakasapl can you fix this one codesniffer warning? (rest of the checks are passing on my latest commit)

A file should declare new symbols (classes, functions, constants, etc.) and cause no other side effects, or it should execute logic with side effects, but should not do both. The first symbol is defined on line 5 and the first side effect is on line 15 (PSR1.Files.SideEffects.FoundWithSymbols)

[hakasapl]

Hi, it's complaining because the function can't be in this file. Could you make that a static function and put it in this file? https://github.com/UnityHPC/unity-web-portal/blob/main/resources/lib/UnitySite.php

That should resolve that issue, then you'll have to call the static function from the account page

[hakasapl]

Awesome!