reduce customtypes import

[ceyonur]

Why this should be merged

Importing customtypes and params pkg causes side-effects of libevm. We should reduce importing of those pkgs in custom-facing client code.

AvalancheGo Follow-up PR: ava-labs/avalanchego#3918

How this works

This pull request refactors logging functionality by consolidating and renaming the logging package, alongside minor code improvements and cleanup. The most significant changes include replacing the log and customtypes packages with a unified customlog package, updating imports and references accordingly, and simplifying variable declarations for consistency.

Logging Refactor:

• Renamed the log package to customlog across multiple files, including format.go, handler.go, and logger.go, and updated their package declarations and references.
• Replaced references to customtypes.FlattenLogs with customlog.FlattenLogs in core/blockchain.go, eth/filters/filter.go, and other files.

Code Cleanup and Simplification:

• Removed unused fields (Version and BlockExtraData) and associated logic from ethclient/ethclient.go to streamline block handling, to prevent importing customtypes and libevm side-effects.

How this was tested

Added to imports_test

Need to be documented?

No

Need to update RELEASES.md?

Probably

[tsachiherman]

could you fix the

no required module provides package github.com/ava-labs/coreth/plugin/evm/customlogs; to add it:

lint message ?

maybe you forgot to add customlogs to this PR ?

[ceyonur]

could you fix the

no required module provides package github.com/ava-labs/coreth/plugin/evm/customlogs; to add it:

lint message ?

maybe you forgot to add customlogs to this PR ?

it was gitignored