internal/vcs/git: add ability to get first ever commit in a repository
Created by: slimsag
For backfilling Code Insights data, we need to run type:diff before: after:
searches
for historical timeframes. In this context, we can skip large amounts of timeframes for
a repository if we know when the first commit to the repository was made.
Signed-off-by: Stephen Gutekanst [email protected]