Eventify TemplateDataGenerator and use oojs-ui

Change the ui/data behavior to work with oojs and event emitters,
and replace the gui from jquery ui to oojs-ui.

Changes made:
* Recreate the templatedata editor with oojs and ooui.
* Create a standalone templatedata model with internal validation.
* Allow the user to insert language-specific strings:
  * Allow adding arbitrary languages and values
  * Normalize output between language object and 'simple' string
  * Add new language code by searching for its name or code
* Import parameters from template code
  * If the template is in subpage and there is no code in the
    current page, the code will request the contents of the parent
    page.

Change-Id: I985ea03dfee58984ec22ec9a157a00968bfca878
Merge "Eventify TemplateDataGenerator and use oojs-ui"