feat: Add support for Dart

[ianlewis]

Description:

Add support for Dart.

Related Issues:

Fixes #1612

Checklist:

• Review the CONTRIBUTING.md documentation.
• Add a reference to a related issue in the repository.
• Add a description of the changes proposed in the pull request.
• Add unit tests if applicable.
• Update documentation if applicable.
• Add a note in the CHANGELOG.md if applicable.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.55%. Comparing base (7520691) to head (f8202ca).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1626   +/-   ##
=======================================
  Coverage   76.55%   76.55%           
=======================================
  Files          19       19           
  Lines        1203     1203           
=======================================
  Hits          921      921           
  Misses        205      205           
  Partials       77       77           

Files with missing lines	Coverage Δ
internal/scanner/languages.go	100.00% <ø> (ø)