support rich-text fieldType in static text component

### Expected Behaviour
This should be changed dynamically on authoring when rich text is selected.
### Actual Behaviour

### Reproduce Scenario (including but not limited to)

#### Steps to Reproduce

#### Platform and Version

#### Sample Code that illustrates the problem

#### Logs taken while reproducing problem

Start by locating the static text component and its authoring behavior in the repository, then trace how the fieldType changes when rich text is selected. Confirm the expected dynamic change in the authoring UI and add or update coverage so the rich-text selection is handled correctly.

Written by the indexing model from the issue text.