function FormFieldTypeAtPoint(X, Y: Double; out FieldType: TPdfFormFieldType): Boolean;
Uses PDFium native page-space hit testing to identify the form field at X and Y without allocating an annotation handle
Returns true and fills FieldType when a widget is present, otherwise returns false and sets FieldType to fiUnknown
TPdfFormFieldType covers fiUnknown, fiPushButton, fiCheckBox, fiRadioButton, fiComboBox, fiListBox, fiTextField, and fiSignature, plus the XFA-only fiXfa, fiXfaCheckBox, fiXfaComboBox, fiXfaImageField, fiXfaListBox, fiXfaPushButton, fiXfaSignature, and fiXfaTextField, which occur only when the loaded PDFium module was built with XFA support and the document has XFA fields
An active page and initialized form-fill environment are required