repositories graphql resolver should allow for regex search

[emidoots]

It has the ability to do so on the backend, we just don't expose it. It would be nice when trying to query repositories on Sourcegraph selectively (such as all repos from multiple orgs).

This is also useful when trying to list repositories programmatically and get back repositories only ending in e.g. example excluding example-foobar

Requested by https://app.hubspot.com/contacts/2762526/company/407948923

[emidoots]

I missed landing this in 3.4, but I think the customer need here is actually mitigated by a new src CLI approach we set up. I'll backlog this for now and reconfirm with customer at a later date.