Support Partial Clone

Dolt supports Shallow Clone:

https://www.dolthub.com/blog/2024-02-21-shallow-clone/

This allows you to only pull to a certain depth of history.

There is also Partial clone:

https://git-scm.com/docs/partial-clone

Partial clone only clones a certain set of the files in a Git repository. This is potentially less useful in the Dolt context because of foreign keys and joins.

But in the shallow clone issue, another user asked for partial clone as well. This is the tracking issue for that feature request.