chore: Fix deprecated vscode Python formatter
The python.formatting.provider setting was deprecated in favor of
having a separate extension for each Python formatter and using
editor.defaultFormatter instead. This adds a recommendation for the
Black formatter extension and selects it for Python files.
chore: Limit vscode Python analysis paths
This limits vscode's Python analysis to the scripts folders so it
doesn't slow down trying to scan all of Zephyr.
Added settings to format various file types on save in VS Code.
Added some recommended VS Code extensions:
- Prettier for formatting various file types
- Python for formatting Python files
- C/C++ for formatting C files
- Devicetree for syntax highlighting
- CMake for syntax highlighting