add `--follow` to git log command that shows history

Created by: danielpops

Feature request description

the --follow flag can be passed to git log for individual files and it will show the history even for files that have moved locations or even repositories.

In sourcegraph, it would be nice if by default, --follow was added to the git log command that generates history / blame annotations.

Is your feature request related to a problem? If so, please describe.

Yes, I cannot see the whole history of a file that has been moved in sourcegraph, and need to clone the repo and view the history manually :(

Describe alternatives you've considered.

I need to clone the repo and view the history manually :(