Keep chainId at just a single place about contracts

[0xAshish]

@atvanguard actually it was at a single place in the beginning 😆

[atvanguard]

Well, do you think the reason could be that "in the beginning",

1. childERC20 / childerc721 tokens did not know how to execute transferWithSig orders for marketplace. That was added here.

2. We did not have marketplace predicate.

3. We did not have tests for marketplace

4. We did not have tests for marketplace predicate.

There was no way you would end up having that duplicated across several files 🤣

[cumpsty]

I'm interested in helping out. Is this a good issue to get started with? Anything I should know?

[atvanguard]

Hey @cumpsty Thanks for the interest! Glad to hear you'd like to work on it.

Anything I should know?

Nothing specific, just check all the places chainId is being used in contracts and let's keep that at in a single place that others can inherit from. Same for tests. Need this done a little urgently :)

[atvanguard]

Hey Cumpsty,
Sorry we needed this done soon, so I rolled out a fix. Happy to help on any other feature you'd like to work on.