Sim refactor 2: move GenesisState generators to modules

[fedekunze]

Closes: #4298

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[rigelrozanski]

New changes look good!

[alexanderbez]

ACK 🎉

[alexanderbez]

Let's not merge until we figure out why test_sim_nondeterminism is 2x slower (~40m+)

[alexanderbez]

@fedekunze Let's turn off invariants for test_sim_nondeterminism. They're checked in regular simulations anyway.

[fedekunze]

Interestingly enough, the invariants aren't run on test_sim_nondeterminism

[fedekunze]

@alexanderbez @rigelrozanski I'd vote for merging this as it and fix #4963 in a separate PR. cc: @tnachen

[alexanderbez]

Interestingly enough, the invariants aren't run on test_sim_nondeterminism

Are you sure?

test_sim_nondeterminism:
	@echo "Running non-determinism test..."
	@go test -mod=readonly $(SIMAPP) -run TestAppStateDeterminism -Enabled=true \
	    -NumBlocks=100 -BlockSize=200 -Commit=true -v -timeout 24h

flag.IntVar(&flagPeriodValue, "Period", 1, "run slow invariants only once every period assertions")

Seems like the default is to run every block? Also, looks like this PR updates it to run every 5 blocks now.