Move the barcode and location widget implementation from `catalog` showcase into the `datacapture` library

We implemented the barcode and location widget as proof of working with custom widgets. Should we contribute these particular ones to the library? The barcode one for example would be a useful widget to have.

_Originally posted by @ellykits in https://github.com/ohs-foundation/kotlin-fhir-data-capture/pull/2#discussion_r3182560053_
            