Add RBF option to name_new/firstupdate/update

[JeremyRand]

Is your feature request related to a problem? Please describe.

The send RPC method supports a replaceable option. Unfortunately, this is not supported by the name RPC methods.

Describe the solution you'd like

Add the replaceable field to the options parameter of the name RPC methods, for parity with currency transactions.

Describe alternatives you've considered

N/A.

Additional context

N/A.

[domob1812]

I believe RBF itself is not supported by the core mempool logic yet - at least I recall something about this back in the day when we added it (and you tried to implement it with Electrum). That's not opposing this feature of course, just mentioning that we likely need to implement that first (and I'm not sure how high priority it is tbh).