3912 Remove Add new tags field from wrangling pages

https://code.google.com/p/otwarchive/issues/detail?id=3912

The wrangling pages have a field that lets wranglers add new tags of the type being viewed (e.g. new character tags if they're wrangling a character tag) to the fandom. According to the wranglers, this field is mostly superfluous and not useful -- it only allows canonical tags to be added, and duplicates a function available on the tag edit page for the fandom.

This removes that field.