Ability to disable and suppress all errors but those explicitly enabled

Would be awesome to have something where I could tell Pyrefly to disable all errors except what I pass in. Same with doing suppressions. This would make it easier to migrate some projects if I'm focusing on one error at a time, which works well with the way that we can enable/disable by config error.

This could be a big motivator for error profiles (all off, strict, basic/default, ...)