This adds the Python files in the tests/ directory to be formatted with
./tools/codeformat.py. The basics/ subdirectory is excluded for now so we
aren't changing too much at once.
In a few places `# fmt: off`/`# fmt: on` was used where the code had
special formatting for readability or where the test was actually testing
the specific formatting.
Configurable via MICROPY_MODULE_GETATTR, disabled by default. Among other
things __getattr__ for modules can help to build lazy loading / code
unloading at runtime.