[Program Forms] Dimension field (?) with limited values per form

[knomepasi]

Ropecon has several dimensions including values that only make sense for a subset of the forms. As dimensions are not currently implemented, we're adding single-/multiselect fields to populate these dimensions. While doing this, we are not adding all values to every form as some of them would not make sense and make the form harder to read for the person offering program.

In case there will be a dimension field type, I hope there is a way to limit the values shown per form.

[japsu]

#643 is this exactly.