Add ENR test

[kamilsa]

• Added a new test suite enr_test under tests/unit/serde with comprehensive unit tests for ENR encoding and decoding, including round-trip tests, deterministic encoding checks, and decoding of a real ENR string.
• Enhanced the ENR decoding logic in enr.cpp to skip unknown key/value pairs instead of asserting, and added a warning log for each unknown key encountered during decoding.

[Copilot]

Pull Request Overview

This PR adds comprehensive unit tests for ENR (Ethereum Node Record) encoding and decoding functionality and improves the robustness of ENR decoding by handling unknown key/value pairs gracefully instead of asserting.

• Added a complete test suite with round-trip tests, deterministic encoding verification, and real ENR string decoding
• Modified ENR decoder to skip unknown keys with warning logs instead of crashing
• Integrated the new test suite into the CMake build system

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
tests/unit/serde/enr_test.cpp	New comprehensive test suite for ENR encoding/decoding with three test cases
tests/unit/serde/CMakeLists.txt	New CMake configuration for the ENR test suite
tests/unit/CMakeLists.txt	Added serde subdirectory to unit test build
src/serde/enr.cpp	Enhanced ENR decoder to handle unknown keys gracefully with warning logs

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[Copilot]

Pull Request Overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

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