feat(rules): add rule creation form and deletion action

[andrewazores]

Fixes #377

For CORS/devserver testing you may need to use https://github.com/cryostatio/cryostat/pull/838 on the backend.

[jan-law]

This is working well. I'm also assuming when you implement the match expression validation, there'll be some helper text to indicate the correct syntax for that field.

[hareetd]

Works well.

[andrewazores]

This is working well. I'm also assuming when you implement the match expression validation, there'll be some helper text to indicate the correct syntax for that field.

Yea, some helper text and some kind of tie-in to #376 I think. I'll have to experiment with that feature to see what's feasible and how I can present it.