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.
This conditional import was only used to get the tests working on the unix
coverage build, which has now switched to use VFS by default so the uos
module alone has the required functionality.
Damien George