set_response_appearance
Description:
Sets the appearance for response.
<picture> <source srcset="message-dialog-appearance-dark.png" media="(prefers-color-scheme: dark)"> <img src="message-dialog-appearance.png" alt="message-dialog-appearance"> </picture>
Use `ADW_RESPONSE_SUGGESTED` to mark important responses such as the affirmative action, like the Save button in the example.
Use `ADW_RESPONSE_DESTRUCTIVE` to draw attention to the potentially damaging consequences of using response. This appearance acts 
      as a warning to the user. The Discard button in the example is using this appearance.
The default appearance is `ADW_RESPONSE_DEFAULT`.
Negative responses like Cancel or Close should use the default appearance.
Parameters:
| this | a message dialog | 
| response | a response ID | 
| appearance | appearance for  |