[Feature] Optimism Block, SubscriptionResult RPC types

[EmperorOrokuSaki]

Component

rpc

Describe the feature you would like

Currently, the Block RPC type is not implemented for Optimism due to the complexities that arise from introducing a generic Transaction to the type.

Similarly, SubscriptionResult does not take a generic at this moment, you can find the relevant discussion to it in the link below.

Additional context

This could potentially be solved by making a transaction trait that can be used to restrict the generic.
Relevant discussion: alloy-rs/alloy#573