resources: Load OOjs UI from its four parts

See the task for more details. This is a backwards-compatible change.
If your script only needs a subset of OOjs UI functionality, you can
use one of the new smaller modules instead of the old big one.

New modules:

oojs-ui-core
  The core JavaScript library.
oojs-ui-widgets
  Additional widgets and layouts module.
oojs-ui-toolbars
  Toolbar and tools module.
oojs-ui-windows
  Windows and dialogs module.

Changed modules:

oojs-ui.styles
  Now correctly only loads the styles needed by OOjs UI PHP.
oojs-ui
  Now just loads core+widgets+toolbars+windows as dependencies.

Using the new modules in I58799e22f9c0a2f78c1b4a02c4b7af576157883a.

Bug: T113677
Change-Id: I0a3bf8fb25fb82325705a473cebd883e20b3ab8d