~ruther/vhdl-i2c

ref: 4314be3c384f967d9d034157ca7b2242cf9708d4 vhdl-i2c/src/mcu_slave d---------
tests: add possibility to check sda stability in mcu_slave
tests: add mcu tests working with slave top designs
chore: fix slave naming in mcu slave designs
feat: add counter and register testing slave top levels