Add UI that makes it easy to bring in new secrets when updating a workspace

[Parkreiner]

Blocked by #807
Will fill in more details later.

Likely going to be related to #681 and #680, so it's probably best that when those issues get resolved, we figure out a general-purpose solution that handles adding missing parameters and secrets.

[Parkreiner]

Being pessimistic and setting this to complexity 5, but depending on how #681 and #680 are implemented, they might help reduce the complexity of this issue