Moves the 256 entry GAMMA table into pimoroni_common.
Should probably be added into a library so MicroPython is built with only one instance of the table.
This change adds a common I2C class, gathering various I2C functions into a single point of responsibility.
It's necessary for correctly managing the I2C bus pins and state across multiple devices.
Add IS31FL3731 driver
Add RGBMatrix5x5 library and example
Add Matrix11x7 library and example
Co-authored-by: ZodiusInfuser <christopher.parrott2@gmail.com>