Required - Readonly mode in star rating component

**Is your feature request related to a problem? Please describe**

I don't have the provision to display star ratings in read-only mode. It would be great feature addition to the module

**Describe the solution you'd like**

Adding a new input property (`readonly`) to the star rating component.

**Describe your use case for implementing this feature**

When user submits a form, you want to display the answers of the form in readonly mode. readonly Star ratings would be useful in that scenario.

**Additional context**

I would like to contribute to this feature request. :)