Include TagField controls in the designer tab order

TagField controls are omitted from the visual designer Tab Order mode even though they accept keyboard focus and participate in Tab traversal at runtime. The mode displays and assigns positions for neighbouring focusable controls, but it shows no badge for a TagField and clicking the TagField cannot assign it a position. The TagField inspector also omits the inherited TabStop setting.

Studio should treat TagField like other focusable text-entry controls so its tab position and participation can be configured in the designer and carried into generated applications.