Instead of registering global variables in a function, make it pure
return the external interface and set it to mw.popups in the
src/index.js entry point.
Explicitly comment on index.js what is being set and why.
Bug: T171287
Change-Id: I94d467bfa7fa6e56033dd254518ad50b5dde5bfc
Changes:
- introduced js module defining mw.popups object
- introduced isEnabled() method which checks the redux store to retrieve
isEnabled status
Bug: T171287
Change-Id: I523369831e2aa8a915ed1cb001b35d13b770f9da