Add LSP and formatter extensions to devcontainers

Proposed changes

Devcontainers for existing benchmarks (cartographer_ros and slam_toolbox) now install RobotFramework extensions as a QoL improvement.

Describe the big picture of your changes here to communicate to the maintainers why we should accept this pull request. If it fixes a bug or resolves a feature request, be sure to link to that issue.

Type of change

[ ] 🐛 Bugfix (change which fixes an issue)
[x] 🚀 Feature (change which adds functionality)
[ ] 📚 Documentation (change which fixes or extends documentation)

💥 Breaking change! Explain why a non-backwards compatible change is necessary or remove this line entirely if not applicable.

Checklist

Put an x in the boxes that apply. This is simply a reminder of what we will require before merging your code.

[x] Lint and unit tests (if any) pass locally with my changes
[ ] I have added tests that prove my fix is effective or that my feature works
[ ] I have added necessary documentation (if appropriate)

Additional comments

Anything worth mentioning to the reviewers.

Ekumen-OS / lambkin