feat: add avoid-dynamic rule

[incendial]

What is the purpose of this pull request? (put an "X" next to an item)

[ ] Documentation update
[ ] Bug fix
[X] New rule
[ ] Changes an existing rule
[ ] Add autofixing to a rule
[ ] Add a CLI option
[ ] Add something to the core
[ ] Other, please explain:

[incendial]

@roman-petrov and this one too, please.

[github-actions]

Dart Code Metrics unused files report of dart_code_metrics. ✅

Summary

• Scanned package folders: bin, example, lib
• No unused files found! ✅

[github-actions]

Dart Code Metrics analyze report of dart_code_metrics. ✅

Summary

• Scanned folders: bin, example, lib, test

• Total scanned files: 384

• Total lines of source code: 6876

• Total classes: 257

• Average Cyclomatic Number per line of code: 0.35 / 1

• Average Source Lines of Code per method: 6

• Total tech debt: 1110.0 hours

• Found issues: 6 ⚠

[codecov]

Codecov Report

Merging #687 (31609ed) into master (67c2f3d) will increase coverage by 0.03%.
The diff coverage is 95.23%.

@@            Coverage Diff             @@
##           master     #687      +/-   ##
==========================================
+ Coverage   86.27%   86.30%   +0.03%     
==========================================
  Files         251      253       +2     
  Lines        5391     5412      +21     
==========================================
+ Hits         4651     4671      +20     
- Misses        740      741       +1     

Impacted Files	Coverage Δ
...c/analyzers/lint_analyzer/rules/rules_factory.dart	95.94% <0.00%> (-1.32%)	⬇️
...s/rules_list/avoid_dynamic/avoid_dynamic_rule.dart	100.00% <100.00%> (ø)
...alyzer/rules/rules_list/avoid_dynamic/visitor.dart	100.00% <100.00%> (ø)

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