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

fix: activate pad_io in open drain on enable = 1

feat: add clear_buffer input to tx

fix: correct delay pulses length

fix: make slave work

feat: add slave top

feat: handle ack in rx, tx

feat(tx): remove unnecessary bit index

feat: add stateful sda, scl switch

chore: use process(all) for combinational processes

fix: tx bugs

feat(rx): make rx idle on start/stop condition

fix(rx): stretching behavior

refactor(rx): do not use unnecessary index

chore: use integer instead of natural when with range

fix: make rx properly working

feat: add possibility for 0 delay in delay entity

tests: add startstop condition detector tests, fix behavior