Support YAML list format for analysis_options includes, and update tests accordingly

[leventkantaroglu]

The getAnalysisOptionsIncludePackage method previously only supported single string includes in analysis_options.yaml files, but modern Dart/Flutter projects often use YAML list format for includes to reference multiple configuration packages. This enhancement adds support for the list format commonly used in projects like:

include:
  - package:flutter_lints/flutter.yaml
  - package:pedantic/analysis_options.1.8.0.yaml

This change improves the dependency validator's ability to detect analysis option packages that should be included in dependency validation, regardless of the YAML format used.