Add diagnostics in the preprocessor

[alessio-perugini]

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• Tests for the changes have been added (for bug fixes / features)
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What kind of change does this PR introduce?

We're adding the diagnostics in the preprocessing part.

What is the current behavior?

Currently, the diagnostics are considered only for the sketch compilation.

What is the new behavior?

The diagnostics field will report errors from the preprocessor and the compiler.

Does this PR introduce a breaking change, and is titled accordingly?

Other information

I'm proposing to use a struct that Stores the information of the diagnostics instead of using a callback approach. We can always revert that.

[codecov]

Codecov Report

Attention: 38 lines in your changes are missing coverage. Please review.

Comparison is base (205a6a5) 68.92% compared to head (be0b8c4) 69.74%.
Report is 7 commits behind head on master.

Files	Patch %	Lines
...lder/internal/preprocessor/arduino_preprocessor.go	0.00%	12 Missing ⚠️
...rnal/arduino/builder/internal/detector/detector.go	46.66%	6 Missing and 2 partials ⚠️
...rnal/arduino/builder/internal/diagnostics/store.go	57.89%	6 Missing and 2 partials ⚠️
...nal/arduino/builder/internal/preprocessor/ctags.go	61.11%	7 Missing ⚠️
...ernal/arduino/builder/internal/preprocessor/gcc.go	40.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2515      +/-   ##
==========================================
+ Coverage   68.92%   69.74%   +0.82%     
==========================================
  Files         204      206       +2     
  Lines       20452    20845     +393     
==========================================
+ Hits        14096    14538     +442     
+ Misses       5207     5166      -41     
+ Partials     1149     1141       -8     

Flag	Coverage Δ
unit	69.74% <61.22%> (+0.82%)	⬆️

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