[Feature] Seperate transactionbuilder trait into non generic part

### Component

rpc

### Describe the feature you would like

ref https://github.com/alloy-rs/op-alloy/pull/557

unifying the transactionrequest type is a bit problematic because this makes the transaction trait ambigious because it has two impls for two networks, leading to clunky api that requires fully qualified path.

ideally this trait is separated into two parts, one that just sets all the fields, and one that actually builds the transaction for that network.

however this would be a smol breaking change

fyi @yash-atreya for context

### Additional context

_No response_