feature/fix-deck-nav

This PR fixes the navigation across all collection and deck UI's. Some pages, such as _add/edit card_, _upload card_, and _add/edit collection_ weren't showing the proper list of collections in the navigation. As a result of this PR, all views use the same datasource and template for displaying the collection and deck navigation.

@jazahn Can you review this?

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[FLASH-165](https://jira.huit.harvard.edu/browse/FLASH-165)