Ability to subscribe to drawer events without initialisation

Secondary nav does not autoCollapse, when the page content has been resized. The autoCollapse is only hooked into the window resize, however in cases when the page is already loaded but the page width changes, then the resize is not handled.

e.g. With the existing sidebar you can change the width of the page but this is not being handled.

We will have to account for this considering the course index bar and block bar which is going to come in (MDL-71209).

Please pull in the branch mentioned above and:

1. Get the primary and secondary navigation to show up in the course page.
2. Look at the autoCollapse of the secondary navigation when toggling the course index list and the block drawer.

There is currently no way to subscribe to drawer events without forcing the drawer to go through it's initialisation process. This is not always required when there are shared files across multiple pages that may not have the drawer present.