Refactoring mw.Feedback to work with OOUI elements
Transform mw.Feedback into an ooui dialog.
* Added a configurable checkbox for useragent and terms
of servvice options. The checkbox can be configured
to be visible or not, and to be mandatory or optional.
(useragent addition based largely on the unmerged
fix I37b1a271af115)
* Transformed the 'feedback-bugornote' message to a
configurable intro message with a link to the feedback
page.
* Added a 'thank you' or 'error' dialog at the end of the
operation indicating whether the feedback was sent or
if there was some error.
Bug: T89878
Bug: T43291
Bug: T35365
Bug: T54588
Bug: T65290
Change-Id: Id1967a83a502f689c40f1af71398c3be99e30640