Adding features from dead extension

[Verseth]

Hi, for a long time the original rubocop extension for VSCode seemed dead (https://marketplace.visualstudio.com/items?itemName=misogi.ruby-rubocop).
So a fork had appeared with additional features like quick fixes, that this extension still lacks.

I think it would be a good idea to port the features from this dead fork.

https://marketplace.visualstudio.com/items?itemName=LoranKloeze.ruby-rubocop-revived
https://github.com/LoranKloeze/vscode-ruby-rubocop-revived