- Introduce `JintJavaScriptEvaluatorTests` to ensure all JavaScript custom functions are available and callable.
- Add `JintJavaScriptFunctionBehaviorTests` to validate execution and behavior of JavaScript functions.
- Extend `WorkflowTestFixture` with `CreateExpressionExecutionContextAsync` for testing JavaScript expressions.
- Update test guidelines with examples for testing JavaScript functions and evaluating expressions.
- Add integration test cases for validating script execution, outcomes, workflow variables, and fault handling.
- Introduce helper methods in `WorkflowTestFixture` for outcome retrieval, activity status, and output assertions.
- Extend test guidelines with usage examples for new `WorkflowTestFixture` capabilities.
- Implement tests to validate execution of valid and invalid scripts, outcome settings, workflow variable access, and complex script handling.
- Add `WorkflowTestFixture` to streamline integration testing setup and execution.
