Rain 2.0: Planned Breaking Changes

[leinardi]

Tracking planned breaking changes for Rain 2.0:

• Make strict-booleans the default behavior
  • Remove the strict-booleans node style and always treat only true/false as booleans.
  • Ensures YAML 1.2 compliance and avoids CloudFormation type mismatches.
• Change casing for stacksets config file
• Remove the --experimental flag from forecast and Rain Modules