Add (or use) QR code widget in Questionnaire

[pld]

Describe the feature request.

• Extend the Android FHIR SDK barcode/QR code reading widget

1. In Questionnaires support setting the field type to "barcode", this renders as the QR code widget
2. QR code fields show as a text entry with a QR code icon to the right of the input field
3. When you tap the icon load a QR code reader, start with the ML Kit barcode reader, note in comments if there are challenges and we need to pursue alternatives
4. After successfully reading a QR code, fill the field with the string read from the QR code
5. The field is read-only, it cannot be edited except by text received from the QR code reader
6. Extend the Questionnaire docs to add this field type

Additional context

• Figma designs and discussion

Acceptance criteria

• [ ] qr-code type in Questionnaire renders the field as a QR code
• [ ] QR code field text cannot be edited manually
• [ ] Clicking QR code icon to right of field loads QR code scanner
• [ ] Scanned QR code populates field
• [ ] If field populated already, scanning a new QR code populates the field
• [ ] On save, text stored in QR code field is stored in a QuestionnaireResponse

Area path

Write a Questionnaire that contains a qr-code type field and integrate the Questionnaire into the app

1. Login to the app
2. Launch the Questionnaire with a QR code
3. Click on the field with the QR code icon
4. Read a QR code
5. Submit the Questionnaire
6. Sync the device
7. Inspect the QuestionnaireResponse stored on the server and device, validate that the QR code data is equivalent

Implementation plan (For Engineers)

• Implement as a widget for QR codes
• The widget uses ML Kit barcode reader to read QR codes