[CompactGate] Generate state transitions of dynamic steps

[taikiy]

Goal

Generate state transitions of dynamic steps. (i.e., BitOpStep)

Context

There are steps that are dynamically generated based on the number of bits, rows, etc., usually using repeat64str macro. Fortunately, these steps have finite number of states, so we can generate the state transitions either in steps file generation or in compile time. We need to take into consideration about the case where there are child steps branching off from the dynamic step.

Currently we do this in collect_steps.py. In the future, we want to do this in compile time with a proc macro, but that requires #704 to be solved first.

[taikiy]

fixed with #771