Add new page location to UI for create page popup after clicking link to non-existing xwiki page

Currently when clicking on an 'empty link' the user gets prompted to pick a template provider, but you aren't prompted where the page should be created (the interface assumes the new page to be a child page).

This has two issues:

1. The template provider can have creation restrictions which causes the user to get 'stuck' with an 'can only create in restricted page space'-error   (bad user experience) 
2. The to-be-created page can have a specific place in the site hierarchy which cannot be configured with the current pop-up.

It'd be nice if the popup was expanded to include a choice where to create the new page.

• This choice can be skipped if the template provider has a single creation restricted (and only makes endpages) - in this case the location the page is created should be the restricted place however (otherwise the user gets 'stuck' on the 'can only create in restricted page space'-error  )