There is a platform, NixOS Linux, on which '/bin/bash' is not available.
This commit changes the interpreter to '/usr/bin/env bash' in some
scripts essential to firmware building.
- fix gazebo SITL debug
- now prompts you to select vehicle
- devcontainer.json container support https://code.visualstudio.com/docs/remote/containers
- this allows you to jump straight into working within a container (px4-dev-nuttx) on a fresh machine
- also helps with Codespaces https://github.com/features/codespaces
- plugin updates
- cpp extension pack, spell checking, CTest support
- cleanup intellisense
- the backup tag parser was a resource hog and didn't work very well
- fix problemMatcher support so that you can click on a build failure
