[Bug] Fix opening from a commit
Description
From this thread:
How do I open files from a commit hash ?
Select a commit hash, browse to a file and then select "open in Web IDE" on the file. IDE fails to load the file/directory.
Implementation plan
- When opening from a branch, we end up using the underlying commit sha most of the time anyways.
- We already have the concept of an "empty branch" (see relevant LOC). Maybe we can leverage this same place to have a "pending branch" or "sha-only ref".