NonZero parameter types

[grarco]

We should consider changing some of the primitive integer parameters to their NonZero equivalent

Originally posted by @sug0 in #3318 (comment)

[brentstone]

how meticulous should we be about this? If we want, we can change a lot of protocol and genesis params?

[cwgoes]

Does this type change also change the formatting which must be used in the genesis parameter files?

[Fraccaman]

it does yeah

[tzemanovic]

I don't think it changes format- they have the same layout and bit validity except for 0.

That being said, I don't know if using NonZero types gives us much benefit except for rejecting 0. Alternatively we could put any invariants in fn validate_parameters in crates/apps_lib/src/config/genesis/templates.rs and each VP that has parameters should also guard its invariants in its VP implementation (see e.g. crates/proof_of_stake/src/parameters.rs fn validate). I think this is more flexible as we can express more rules than just non-zero.

[Fraccaman]

Okay makes sense I think we can close this one then.