Add support for Attachment itemControl type

[fredhersch]

Is your feature request related to a problem? Please describe. As a user, I want to add an image to a patient record as part of an encounter (e.g. attaching image of a consent signature to a record)

Describe the solution you'd like Provide support for the item-type-attachment within the SDC Library of the SDK.

• This would create an button that allows a user to select a file OR capture an image directly from a camera
• On submit, the media attachment - which can be any binary data - is stored as an Attachment value type

See https://hl7.org/fhir/codesystem-item-type.html#item-type-attachment

Additionally, there should be validation on the media types and file-size of the item being uploaded. Propose this is by default set to:

• File size: 1mb
• Media types: jpg, png, .mp3, .mp4, pdf

@shelaghm can you provide a Ux flow for this

cc: @joiskash @dubdabasoduba @f-odhiambo