big-image and media::big-image column heading for itext tag is not available in XLSForm

[mitchellsundt]

There is a "big-image" itext value tag type that is not supported by XLSForm.

Usage section below is copied from this page: https://opendatakit.org/help/form-design/guidelines/

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Itext value tag types

The possible choices for the form attribute of the itext tag are:

"long",
"short",
"image",
"audio",
"video", and
"big-image".

By default, itext "image" values are not clickable. However, if you also include a "big-image", the image displayed by "image" will be clickable and will display a pannable, zoomable view of the file specified by "big-image". You can return to your form after opening a "big-image" by hitting the phone's "back" button. Specifying "big-image" alone has no effect, you must always include "image".

Files referenced by "image" and "big-image" may be the same; however, to improve the user experience, we highly recommend creating smaller thumbnail images to be referenced by "image" (images will display faster if they do not need to be dramatically scaled down).

[MartijnR]

+1