[TemplateScript] update for OOjs UI

[Pathoschild]

MediaWiki recently added OOjs UI to the move page form. This breaks any scripts that interact with the fields, since OOjs wraps them with its own UI. Look into programmatically interacting with OOjs when it's present.

[ricordisamoa]

OO.ui.infuse( $( '#wpReason' ) ).setValue( 'foo' )