tools: (VERA) Reduced some common duplicate code

[tcoyvwac]

• Moving some common code to their own local functions and/or preferring to use some available standard-library algorithms (which performs the same thing).
• Also using a simple keyword datatype to hopefully make the code more readable and modular.

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(This is the VERA branch version of (ADA) PR:#275) (The PR's commits were cherry-picked and adjusted from the ADA version)

[patriciogonzalezvivo]

Hi @tcoyvwac ! I think I already merged this changes on the vera branch

https://github.com/patriciogonzalezvivo/glslViewer/blob/vera/src/tools/text.cpp

But probably I'm missing something. Sorry for the confusion and the slow replay. I'm on vacations and more sporadic that usual.