test: add E2E infrastructure test for BiniBFT node consensus flow

[rockaxorb13]

Description

This pull request introduces an automated End-to-End testing suite for the core BiniBFT node infrastructure using the Ginkgo and Gomega frameworks already present in the go.mod dependencies.

Currently, the standalone testing apparatus relies on manual observation of terminal logs via main.go. This suite establishes a programmatic control model that bootstraps a localized 2-node cluster, submits an ASN.1 serialized transaction, and mathematically asserts the network state via the operational HTTP API.

Changes Made

• Added chain_e2e_test.go to the main package directory to avoid cyclic import restrictions.
• Configured isolated temporary directories for the LevelDB and Write-Ahead Log instances to ensure a self-cleaning test environment.
• Implemented a 2-node map configuration to satisfy the ComputeHierarchy sharding requirements.
• Updated go.mod and go.sum to reflect the downloaded Ginkgo testing dependencies.

Testing

• Test suite executes successfully via standard Go testing tools.
• Verified both nodes successfully elect a leader and process the incoming transaction without panicking.