Remove usages of `ProtoBytes` from `swirlds-state` modules

Currently `testFixtures` of `swirlds-state` modules extensively use `ProtoBytes` type which comes with HAPI dependency. Though it's not as critically important as production dependency, it should be eventually removed. Usages of `ProtoBytes` should be replaced with `Bytes` and corresponding codec

Start by searching the swirlds-state testFixtures for all ProtoBytes usages and inspect the surrounding codec patterns. Replace those usages with Bytes and the corresponding codec; done means the swirlds-state testFixtures no longer use ProtoBytes while their tests and builds still pass.

Written by the indexing model from the issue text.