The model will be used for logic, so the full hash is needed there; a shortened
hash of 8 characters might be too short to be unique in very large repos. If
some view wants to display a shortened hash, it should truncate it at
presentation time.
We've been sometimes using lo and sometimes using my slices package, and we need to pick one
for consistency. Lo is more extensive and better maintained so we're going with that.
My slices package was a superset of go's own slices package so in some places I've just used
the official one (the methods were just wrappers anyway).
I've also moved the remaining methods into the utils package.
This fixes pkg/integration/tests/worktree/rebase.go which was failing on old git versions due to a difference in
order of branches that don't have recency values
test: add an integration test for checkout branch by name
fix: fix full ref name of detached head
refactor: refactor current branch loader
chore: use field name explicitly
