chore: Added more linter rules and minor fixes

[albertodev01]

Why?

There should be some more linter rules to add and a few minor fixes for the Flutter and Dart examples

What?

I have updated the analysis_options.yaml file and updated the Dart and Flutter examples

Types of Changes

• General improvements (quality updates to improve the stability of the project)

Notes

n/a

Checklist

• I have provided a description of the proposed changes.
• I added unit tests for all relevant code.
• I added golden tests for all UI changes.
• I added documentation for all relevant code.

[codecov-commenter]

Codecov Report

Merging #33 (446cdf5) into master (aebe4bb) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master       #33   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           67        67           
  Lines         3004      3004           
=========================================
  Hits          3004      3004           

Impacted Files	Coverage Δ
lib/src/system/utils/matrix/real_matrix.dart	100.00% <ø> (ø)
lib/src/utils/complex/complex.dart	100.00% <ø> (ø)

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