Switch to repo submodule from setup folder

[OrionOth]

This begins the standardization process on the setup repository, rather than just having the folder as part of the parent repository as we did previously. This has the advantage of making it easier to migrate setup changes between different years/robots more easily, and this carries over to this repository as well with the seahawk_1 branch.

[mike-matera]

I don't think I want this right now because using a submodule complicates the process of adding and removing users from the Raspberry Pi. The current process is:

1. Edit and commit the rov.yaml playbook.
2. Push the change to the main branch of the 23 repo.
3. Any user on the ROV can pull main and re-run make rov-install and the updates are made.

With the setup directory in a submodule the process becomes:

1. Edit and commit the rov.yaml playbook in the setup repo.
2. Push the change the the setup repo
3. Make a "bump" commit to the main branch of the 23 repo to associate the new setup ref
4. Push the change to the 23 repo
5. Any user on the ROV can pull main and re-run make rov-install and the updates are made.

The submodule process is going to result in a bunch of senseless "bump setup version" commits in this repo. That's going to be annoying for everyone.

[OrionOth]

This commit was modified to remove the change on the h264_image_transport submodule and move it to #171 instead.

[OrionOth]

This PR is on hold until we get CI (GitHub Actions) working.