FB: Consider migrating fr:dropdown-select1 and fr:image

[ebruchez]

When we introduced fr:dropdown-select1, the XForms engine did not have native support for matching on appearance or other attributes. Since #1936 this is supported, and since #2241 bindings in the XForms namespace are supported. So we should be able to directly use xf:select1[@appearance = 'minimal'] in the form source.

Similarly, xf:output[@mediatype = 'image/*'] maps to fr:image.

Tasks:

• implement migration back to xf:select1[@appearance = 'minimal'] in annotate.xpl
  • check that Form Builder behaves properly (toolbox, FB dialogs, appearance selector)
• consider whether using xf:output[@mediatype = 'image/*'] would be better than keeping fr:image
• implement migration back to xf:output[@mediatype = 'image/*'] in annotate.xpl

[ebruchez]

Form Builder should standardize on the representation with appearance="dropdown".