~ruther/vhdl-i2c

ref: bb5425f814e0c7f09683432e4cc8b1950d1c57eb vhdl-i2c/src/utils d---------
fix: activate pad_io in open drain on enable = 1
fix: correct delay pulses length
chore: use integer instead of natural when with range
feat: add possibility for 0 delay in delay entity
fix: compilation errors
feat: add utility entities

Delay, metastability filter, open drain buffer, synchronous edge detector