Use HTMLAutoCompleteSelectField

Use the new field type added in core in I42473cea for the wiki selection
widget.

Change-Id: I8f2fb3aea1d628fb31464f9245c2f3aa5ad195d2
Depends-On: I42473cea75f3706cc0125167f9191275ca6cb3b0
Merge "Use HTMLAutoCompleteSelectField"