Controller responsible for dispatching UI5 Actions.
Flow:
- Resolves the Action artifact from the Ui5Context/registry.
- Resolves the ActionHandler behind the Action (getHandler() is a class-string).
- Injects parameters, settings, and a method-injected FormRequest if the
handler declares one (the invoker owns that resolution + validation).
- Executes the handler and returns the result (JSON by default).
Notes:
- Actions are state-changing operations (POST/PATCH/DELETE).
- Unlike Resources, they may not be idempotent.