chore: curry extrinsic effect factory

[harrysolovay]

A previous PR introduced currying of the (client) first param of RPC effect factories. The thinking was that this would simplify codegen. One could effectively swap out a single statement in a generated file to inform the discovery value and RPC error signatures. Aka.

generated.ts

// codegen-replacement-start
declare const client: Effect<rpc.Client<any, any, any, any>, Error>;
// codegen-replacement-end

export const getMetadata = C.state.getMetadata(client);

Then, the user could import generated.ts and interact with the effect factory without needing to think about the client's provider type and discovery value.

This PR does the same for the extrinsic effect factory. More to come later.

[kratico]

LGTM