Improve build.sh script for Debian package

[mdkhurram0207]

This pull request enhances the script/build.sh for building the Debian package by:

• Adding stricter shell safety with set -euo pipefail.
• Verifying all required packages (devscripts, debhelper, build-essential) before building.
• Aggregating missing package checks and providing a single actionable error message.
• Using robust file detection to locate the generated .deb file.
• Ensuring build artifacts are cleaned automatically on script exit.
• Adding colored, human-readable status messages for better user experience.

These changes make the build process safer, more user-friendly, and less error-prone.

[mdkhurram0207]

@bramj Could you please review this PR? It improves the build.sh script for safer execution and better dependency handling.