Sort transports generated by testing plugin

[tchssk]

This pull request enhances the scenario-based testing code generation for services by improving how supported transports are handled and by adding comprehensive scenario type definitions for different service configurations. The changes increase maintainability and extensibility of the test code, especially around transport handling and scenario structure.

Enhancements to transport handling:

• Refactored the way supported transports are collected and sorted for each method, using maps.Keys and slices.Sorted for clarity and correctness in buildScenariosData. [1] [2]

Expanded scenario type definitions for test code:

• Added new scenario type code snippets (ScenarioTypesWithPayloadCode, ScenarioTypesWithResultCode, ScenarioTypesWithoutPayloadResultCode) that define the structure of scenarios, steps, expectations, and transport availability for each service configuration. These definitions are now included in the generated test code for services with payload, with result, and without payload/result. [1] [2] [3]
• Updated the scenario test cases in scenarios_test.go to expect the new scenario type code snippets in the generated output, ensuring tests cover the new scenario structure.

[raphael]

This is great! Thanks for tightening up the generated scenario output and adding coverage for the scenario types. One small follow-up: buildScenariosData now sorts the per-method TransportAvailability, but ValidTransports is still populated from map iteration and is used by the example scenarios template. Could you sort that slice too so the example YAML is deterministic as well?

[raphael]

Thank you!