Support for state override parameter in some RPC methods

[alexb5dh]

Resolves #4021, resolves #6120, resolves #7306.

Changes

• Support for state override set in the following RPC methods:
  • eth_call, eth_estimategas
  • trace_call
  • debug_traceCall
• Makes following methods to run on top of the specified block instead of the previous one, similar to other clients:
  • trace_call, trace_callMany, trace_rawTransaction
  • debug_traceCall
• Prepared context to test debug module with minimal mocking and added some basic tests.
• ~~Fixes double-serialization of some of the parameters in the RPC tests.~~

What types of changes does your code introduce?

• [x] New feature (a non-breaking change that adds functionality)

Testing

Requires testing

• [x] Yes

If yes, did you write tests?

• [x] Yes

Documentation

Requires documentation update

• [x] Yes

Requires explanation in Release Notes

• [x] Yes, RPC changes should probably be included.