Add the ability to revert to a previous version of a yara rule in the UI

[danny248]

No description provided.

[dcuellar322]

@danny248 Done. #382

I added some comments. Please review.

[dspruell-i01]

We were unable to validate this feature; we can see how to view revisions in the UI, can perform and view diffs between versions, but don't seem to see a way to revert to a previous revision. Not completely sure how this would be visible in the UI.

@WillyMac indicated that this was implemented at some point in the past, but seems to have been either changed or removed or perhaps affected by a regression.

@dcuellar322 We'd like to take another look at this one if we can, as the capability to roll back to a previous revision is an important one and in a future state where we replace signature management in ThreatKB with a GitHub driven approach, we'd have this capability there (native VCS revision control based reverts). We might be missing something, but don't think we see this in the UI.

[dcuellar322]

@dspruell-i01 That's definitely weird. I don't see the ability either. I don't know what happened to my previous code. It was merged into staging almost 4 years ago lol.

I can reference the MR and reimplement.