ExpectedUsage should be able to filter by path prefix

[markusreil]

I'd like to be able to split my API tests over multiple test classes but keep using the ExpectedUsage rule.
I'm thinking of being able to pass in a path prefix (e.g. "/api/someResource"). The rule would then only check for unused stuff within that prefix.

If anybody would be interested in a feature like that, I can get a PR ready for this pretty quickly.
Just wanted to get some feedback before I get started.

[nidi3]

Sounds like a legit case to me.

[LessMo]

Any progress or plan for this feature ?
@markusreil @nidi3