Add "robot" container (backport #221)

[mergify]

Changes Made

The existing Dockerfile defines a "robot" stage which contains the Blue source and some deps but no other dependency repos from blue.repos. This means "robot" is not runnable "out of the box," requires multiple manual stages (vcs import ..., rosdep ..., colcon build ..., etc ) to make it runnable.

This PR:

• Renames the "robot" stage as "blue_src_and_deps"
• Updates "robot" to include all dependencies of "blue" and "colcon build"

The PR is opinionated:

• That a "robot" stage should exist
• That blue.repos should be split into separate blue_robot.repos (no ros_gz) and blue_sim.repos (adds ros_gz). Might be another way to solve this problem.

Testing

Ongoing.

---

This is an automatic backport of pull request #221 done by Mergify.

[mergify]

Cherry-pick of ba77c25 has failed:

On branch mergify/bp/humble/pr-221
Your branch is up to date with 'origin/humble'.

You are currently cherry-picking commit ba77c25.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	new file:   .devcontainer/robot/Dockerfile
	new file:   .devcontainer/robot/devcontainer.json
	modified:   .docker/Dockerfile
	new file:   .docker/compose/robot.yaml
	modified:   .dockerignore
	new file:   sim.repos

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   blue.repos

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[amarburg]

The git branch for ros_gz needs to be changed in sim.repos to "humble". I'm testing this now.