Provide rpc that can generate AA account contract address (silius specific endpoint, silius_)

[octavei]

Provide rpc that can generate AA account contract address. Usually, we can generate the contract address of the AA account according to the initcode. This address can be calculated in advance under the chain. It will be much better if we provide an rpc to obtain the AA address to the user.

[zsluedem]

We should extend rpc to a new domain like silius_xxxxx. Actually i am not sure whether this is a good feature for bundler. This should be easily got from eth_call method with latest entrypoint contract