Fixed MicroPython support

This release ships a fix for MicroPython as it does not support usage of __bytes__ when calling bytes() on a LppFrame or LppData instance. Specifically, you need to use LppFrame.to_bytes() in MicroPython or for portable code in general.

What's Changed

• fix: add to_bytes() helper for MicroPython by @smlng in #105

Full Changelog: v2.3.0...v2.4.0