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Remove Go install script and refine Dockerfile and server.go

Deleted the standalone Go installation shell script, and made changes to both Dockerfile and server.go to optimize our app build process and provide enhanced server feedback.

Our Go applications are now built directly using Docker which reduces the setup complexity. Hence, the install_go.sh script is no longer needed. In Dockerfile, additional networking tools (ping and mtr) are now included in the image for better network diagnostics. In the server.go file, the response now includes detailed failure message for better troubleshooting. Also, commented code has been removed to clean up the codebase.