feat: partially implement channel widths

Merge pull request #25 from Rutherther/feat/subclass-1-support

Add subclass 1 support

feat: change behavior of asserting link nsynced only on frame clk (subclass 0) and multiframe clk (subclass 1)

fix: deassert sync on LMFC falling edge to match the standard

feat: add basic subclass 1 support

chore: specify ranges for all integers

Ranges are not needed inside of tesbenches.
Resolves #22.

feat: assume full synchronization after 4 correct 8b10b characters are received after 4 /K/ characters

Resolves #23.

feat: make sync aligned to frame clock

Resolves #21

feat: move all link configuration to generic instead of ports

Configuration is same for one compilation, it cannot change.
Thus it does not make sense to be a port.
Resolves #13.

chore: add documentation to the code

feat(link): add link controller