Missing patches from microbit-v2-samples

[microbit-carlos]

I'll create a list here of missing patches from https://github.com/lancaster-university/microbit-v2-sample that might require some discussion before merging them here:

• build: Add an option to checkout a specific revision of the target
  • lancaster-university/microbit-v2-samples@9da3427
• Updated build.py (and libs) to have extended --status functionality
  • lancaster-university/microbit-v2-samples@c576ffd
• Added a -j/--parallelism flag to build.py to control the number of build threads
  • lancaster-university/microbit-v2-samples@c854391
• Removed F-strings from the build tools to maintain Python 3.2 compatability with upstream toolchains. Added new functionality for --status
  • lancaster-university/microbit-v2-samples@f4aaca3