Legacy XFA combo and list fields

THotPDF.ApplyXFAAsAcroForm creates native combo and list widgets using the same detached choice graph as the portable consumer

Actual saved fields preserve separate display and export option pairs, padded UTF-8 exports, scalar or multiple values, selected indices, list top index, editable and read-only flags, commit-on-selection and text alignment

Repeated instances retain distinct field names and their own selections; runtime event changes survive native XDP save/reload and failed events restore both values and body font styles

When AutoFormAppearances is enabled, the consumer reads the actual installed Windows font program for the authored family, weight and posture, embeds it, registers its default font resource and paints Unicode display labels at the authored size, color and alignment

AutoFormAppearances=False keeps the native choice state without loading an installed font or generating AP; PDF 2.0 forces native appearance generation

Candidate preparation completes before document graph mutation; each actual choice field is adopted in one graph transaction, with cancellation and failure restoring the prior field list, font registrations, annotation identity and drawing font resources

The transaction covers one choice field; previously completed fields and layout-created pages belong to the surrounding ApplyXFA operation and are outside that field transaction

Unsupported selected glyphs raise a font error before committing a partial widget; the caller may correct the input or font and retry on the same document

The current choice appearance consumer covers body text and list selection paint; external or rich choice captions and authored frame decoration require separate consumers

This change does not add XFA choice scripting methods such as addItem, deleteItem or setItemState, or add reset defaults beyond the existing choice value contract