Move repository URI normalization out of PullLocalDaemon

Summary: Ref T4327. Moves us one small step forward toward testable change parsers by separating out this unrelated logic from the PullLocal daemon. We will also probably want to run this logic so we can do remote path lookups to limit the role of Arcanist Projects in the future, which is why I made the URI type (here, only "git") a parameter rather than calling this a GitURINormalizer or something.

Test Plan:

• Ran unit tests.
• Ran repository discover on a correctly-configured remote repository.
• Ran repository discover on an incorrectly-configured remote, got an error message.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T4327

Differential Revision: https://secure.phabricator.com/D7981