feat(version): add support for monorepos

[dhruvdutt]

The .git folder lookup in version command is based on localPrefix which is not the right location always for monorepos where .git folder is at a different location and not there npm version command is executed.

Fixes by doing the right lookup that will support .git in monorepos.

References

Fixes #1082, #9111

[dhruvdutt]

@ruyadorno Can you please guide on fixing tests?

[ruyadorno]

hi @dhruvdutt my understanding here is that tests are failing because they were relying on the fact that in the nested folder from which the commands are run (in the context of these tests) there is no .git folder, that would cause the command to fail, which is the expected behavior being asserted in these current failing tests: https://github.com/npm/cli/blob/latest/test/tap/version-lifecycle.js#L62

Since the git rev-parse command will work from any sub-directory of a git repo, the proposed change from this PR will result in these assertions failing - since the statGitFolder call will now succeed instead of failing as it was the case before, because it's reading rev-parse info from the repo itself 😁

Now some important considerations: It's worth noting that we're heading towards end of beta for npm7 and this command has been entirely rewrote for the new version and this logic now lives on: https://github.com/npm/libnpmversion - so maybe a more long-lasting contribution would be to validate how it's currently behaving in the v7 beta and contribute the fixes to libnpmversion instead? (IMO this fix is actually very important in v7 since that's the first version which will ship with support to workspaces but I'm not sure if it's still behaves the same in v7)