Fixes #3090 and #2575 - Treats .git/gitdir as cwd on "empty" bare clones

[hwangh95]

Description

There are cases for having bare clones with multiple worktrees in the same folder to manage various versions in a workspace

Currently, however, the only supported way to do this is to have the .git/ files such as HEAD, branches/, refs/, worktrees/, etc in the same folder as your actual worktrees. This makes your workspace very cluttered and is counterproductive to the structured way of multiple worktrees

What many of us prefer is to have an "empty" bare clone with the normal bare clone files within the .git/ folder or another folder labeled .bare and use a .git file with a gitdir reference

This fix will allow for the worktrees view to function the same way it would show on a git worktree list command

Checklist

• [x] I have followed the guidelines in the Contributing document
• [x] My changes follow the coding style of this project
• [x] My changes build without any errors or warnings
• [x] My changes have been formatted and linted
• [x] My changes include any required corresponding changes to the documentation (including CHANGELOG.md and README.md)
• [x] My changes have been rebased and squashed to the minimal number (typically 1) of relevant commits
• [x] My changes have a descriptive commit message with a short title, including a Fixes $XXX - or Closes #XXX - prefix to auto-close the issue that your PR addresses

[hwangh95]

@eamodio Hello, could you please have a look at this PR?

[hwangh95]

@d13 Hey sorry for the ping but could you look at this PR? Or is there someone else who can? I've been waiting for feedback for about a month now

[hwangh95]

@d13 Still waiting for feedback on this

[hwangh95]

@axosoft-ramint Sorry for the ping, but could I get you to look into this? I've been manually compiling the source every version to fix this issue...

[axosoft-ramint]

@hwangh95 Thanks! It may be a while before I get to this, but it's on my list now.