/collection/new endpoint stages an initial commit

[b5]

This builds on #601, where we're adding in a new way to build initial datasets. For this section let's focus on a route within the collection section at /collection/new that stages a dataset document for initial commit creation. This "new" view should work the exact same as the "status" workbench editor with some exceptions:

• /collection/new should not try to fetch history
• user should be able to edit meta & add a readme in this early state
• It should but have additional validation logic that confirms the dataset will be accepted by the backend:
  • Users must add a body before they can commit, and should have feedback that shows a body is needed
• having a staged body should notify the user that a structure will be inferred for now, and not let them edit structure
• dataset name should be editable from this screen

All of this should be possible as a new route that uses existing components, so this PR should mainly be realized as changes to workbench components & an added route to the collection table.

This PR should not worry about the actual actions that submit & create the initial dataset, instead just work on programmatically navigating to /collection/new. A valid commit should just log the dataset document to the console in the click handler/