This handles the case when no local branch exists. You will get an error
if a local branch with the same name already exists. Better behavior for
this case can be implemented later.

Fixes #54601

Fixes #48714: Added conversion from local case of the file to git case.  This does not fix the view in the Explorer, but this solution should be easy to apply to that issue too.

fixes #48485

fixes #48486

* Instead of testing it through `getCommit` as we don't use stub in test

fixes #46826

Closes Microsoft/vscode#45271

Update src to build with TS 2.7

Explicitly assign this.message in the else body

fixes #40229