WebSocket: Add a quickfix to add missing mandatory parameters

[dalidia]

Description:

Method annotated with@OnError requires a mandatory parameter Throwable. If the user does not include that mandatory parameter, we could include a quickfix that would add that missing parameter.

Specification:

Method annotated with @OnError "can only have [...] a mandatory Throwable parameter" according to the onError specs

Type of language feature proposed:

Select all that apply

• [ ] diagnostic
• [x] quick-fix
• [ ] snippet
• [ ] other, please specify: