[AdaGFX_helper] Reduce build-size

[tonhuisman]

The ever continuing quest of reducing build-size 😃

AdafruitGFX_helper:
Features:

• Reduce log strings by using strformat() and concat() where appropriate
• De-duplicate some code in draw-command handling
• Generic code optimization
• Add Default font selector and support functions
• [P131] Implement default font selector

TODO:

• Testing
• Update [P131] documentation