FiniteStateMachine upgrades

[mkorbel1]

Description & Motivation

This PR has a handful of upgrades to FiniteStateMachines so that it is easier to construct and generate readable FSM code.

• Add labels in generated verilog for FSMs (the final version of this should use SystemVerilog block labels #585)
  • this was removed from this PR, we can leave it to SystemVerilog block labels #585 to handle the labels
• Add a way to set up defaults across all states (namely via setupActions), addressing "Default" values for FiniteStateMachines #509
• Perhaps: addressing Specifying the Sequential vs. Combinational driving of logic in FiniteStateMachine #313, still thinking about how/if to do it here or as a separate component/abstraction
  • an implementation with updates was opened in a PR in ROHD-HCL, but not sure if it will get merged: FiniteStateMachine upgrade with "updates" rohd-hcl#196

This PR also includes some misc lint cleanups for newer versions of Dart

Related Issue(s)

Fix #509

Testing

Updated test for lights to leverage it, confirmed failure if the feature was broken. Added new tests for other stuff.

Existing tests cover much, but need to add more for new features

Backwards-compatibility

Is this a breaking change that will not be backwards-compatible? If yes, how so?

No

Documentation

Does the change require any updates to documentation? If so, where? Are they included?

Updated examples.