This changes the btree implementation to use the buffer protocol for
reading key/values in all methods. `str` and `bytes` objects are not the
only bytes-like objects that could be used.
Documentation and tests are also updated.
Addresses issue #8748.
Signed-off-by: David Lechner <david@pybricks.com>
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.
