fix(evm): correct chain ID extraction and configuration for compatibility tests

[MudDev]

This pull request focuses on improving the handling and extraction of EVM chain IDs throughout the codebase and scripts, particularly to ensure compatibility between the Cosmos chain ID and EVM tooling (like viem). It also introduces a new upgrade proposal for EpixChain v0.5.1. The changes aim to make the chain ID handling more robust and less error-prone, especially in local development and testing environments.

Chain ID Extraction and EVM Compatibility Improvements:

• Refactored the logic in evmd/cmd/evmd/cmd/root.go to prioritize extracting the EVM chain ID from the command flag or context, ensuring that the correct EVM chain ID is set even if the Cosmos chain ID format varies.
• Updated scripts/local_node.sh to delay setting the client chain ID until after epixd init, preventing the default EVM chain ID from overwriting the intended value, and added explicit extraction of the EVM chain ID from the Cosmos chain ID with robust fallback logic. The extracted EVM chain ID is now passed directly to the node startup command. [1] [2] [3]
• Enhanced scripts/tests_compatibility_viem.sh to source the .env file early, convert the numeric CHAIN_ID to the correct Cosmos chain ID format for node startup, and restore the numeric value for viem tests, ensuring seamless compatibility between the node and EVM tooling. [1] [2]
• Updated the .env and test files in tests/evm-tools-compatibility/viem to clarify and enforce the correct EVM chain ID usage, and improved parsing in the test script to ensure the chain ID is always numeric. [1] [2]

Governance and Upgrade:

• Added a new upgrade proposal file proposals/v0.5.1-upgrade-proposal.json for EpixChain v0.5.1, detailing the expedited upgrade, key changes, and instructions for binary verification.