Offer multiple rpc servers to direct calls to different apps

[p-offtermatt]

Is your feature request related to a problem? Please describe.
When e.g. calling the status endpoint https://docs.cometbft.com/v0.34/rpc/#/Info/status,
currently CometMock just uses the first validator and prints information for it.
This means it is hard to actually get information for other validators.

Describe the solution you'd like
CometMock should offer a way to direct calls to other apps/make them look like they hit a specific validator.

One solution for this could be to offer several addresses that cometmock listens on as an rpc server.
Which address a call gets directed to determines which validator it corresponds to.
The addresses could be specified during startup.

Additional context
This issue is currently low priority, since there are workarounds for the use cases so far - e.g. for getting the node-id, the cosmos-sdk offers functionality to get it without having to go through the cometbft rpc server with

gaiad tendermint show-node-id

If the workarounds become too cumbersome for future issues, this should potentially be addressed.