improve error logging

[uziins]

This pull request focuses on improving error handling and logging in the MySQL connection pool implementation. The main changes include switching all logging from console.log to console.error for errors, streamlining and removing unnecessary log statements, and making minor updates to the package version.

Error handling and logging improvements:

• Changed all error-related log statements in lib/mysql.js from console.log to console.error for better visibility and consistency. [1] [2] [3] [4]
• Removed non-essential and verbose console.log statements throughout connection, keep-alive, and shutdown logic to reduce noise and simplify output. [1] [2]

Retry and health check logic:

• Streamlined retry logic in retryQuery by removing redundant comments and log statements, and clarified error handling.
• Simplified health check code by removing unnecessary comments and improving error reporting. [1] [2]

Version update:

• Bumped package version from 1.2.1 to 1.2.2 in package.json to reflect these improvements.