refactor: elcontracts/reader interface

[damiramirez]

What Changed?

This PR aims to improve the elcontracts/reader interface by implementing a request-response pattern. For the exposed functions, we create structs that represent the request (specific fields + BlockNumber) and the response.

Because the function signatures change, we also refactor the tests to align with the new pattern.

Below is a simple example of the new request-response pattern:

Example:

func(r *ChainReader) Foo(
	ctx context.Context,
	request FooRequest,
) (FooResponse, error) {
	...
}

type FooRequest struct {
	BlockNumber *big.Int,
        ...
}

This is a work in progress and changes may occur.

Reviewer Checklist

• Code is well-documented
• Code adheres to Go naming conventions
• Code deprecates any old functionality before removing it

[maximopalopoli]

LGTM, just leave you a comment:

[maximopalopoli]

Question, should this line be left in? Or is the chainReader refactoring not finished yet? The same in the other call to elcontracts.CalculateOperatorAVSRegistrationDigestHashRequest

[maximopalopoli]

Same in the TODO of elcontracts's ChainWriter related to this

[damiramirez]

I added that comment because the avsregistry and elcontracts/writer refactors are being handled in separate PRs. It might be unnecessary to keep this comment since conflicts are expected during merging and will need to be handled regardless. So I will remove the comments!

[damiramirez]

Done d110c54!