feat: add unsupported EthGetTransactionByBlock*

[LesnyRumcajs]

Summary of changes

Changes introduced in this pull request:

• added unimplemented stubs for Filecoin.EthGetTransactionByBlockNumberAndIndex and Filecoin.EthGetTransactionByBlockHashAndIndex. This behaviour matches Lotus's 1.29.0 behavior, and so we are on par with its support. Given the current Lotus-centric testing infrastructure, I believe that's the optimal way to move forward. When Lotus will decide to implement these methods, we'll get a notification.

Reference issue to close (if applicable)

Closes #4701
Closes #4702

Other information and links

❯ docker compose logs api-compare | rg EthGetTransactionByBlock
api-compare-1  | | Filecoin.EthGetTransactionByBlockHashAndIndex (10)   | Rejected("unsupported method")                                                                | Rejected("unsupported method")                                                                                                                                                                                                                                   |
api-compare-1  | | Filecoin.EthGetTransactionByBlockNumberAndIndex (10) | Rejected("unsupported method")                                                                | Rejected("unsupported method") 

https://github.com/filecoin-project/lotus/blob/665cd01a09943f5b7ace541e534c0f2a56b64645/node/impl/full/eth.go#L535C18-L541

Change checklist

• I have performed a self-review of my own code,
• I have made corresponding changes to the documentation,
• I have added tests that prove my fix is effective or that my feature works (if possible),
• I have made sure the CHANGELOG is up-to-date. All user-facing changes should be reflected in this document.