Create an UI to update and test log classifier rule

[huydhn]

Instead of the slow route to submitted PRs to update https://github.com/pytorch/test-infra/blob/main/aws/lambda/log-classifier/ruleset.toml and test it out manually with a mock fixture, it would be much easier to be able to create a new classifier rule and validate it in fly on HUD.

Another idea here is to be able to overwrite the log classifier with results from manual log search and show the latter instead.