Improve Makefile for better maintanability

[tmendonca28]

What does this PR do?

Enhancement: Improvements were made to the Makefile to allow for readability, consistency and adherence to best practices.

Motivation

Reading through and understanding Makefiles, their importance and how to write them in a more readable manner following any related best practices that would enhance its maintainability.

Checklist

N/A

Details

Changes include:

• Utilizing variables for better code maintenance i.e. GOFLAGS & BIN_DIR
• Ensuring make targets are well-documented and self-explanatory
• Provided informative messaging during running targets
• Enabling use of GO modules with "GOMODULE=on"
• Using '@' to suppress unnecessary command echoing

[christophetd]

Looks great! Thanks a lot for the PR. Will let CI run and merge when it passes