Sharing: Fix app navigation layout on small screens

[heikomat]

There exists a css-class to make sure that on small screens, there is space above the content for the nav-bar.
This is only relevant for small screens, because on wide screens the navigation is on the left side.

wether a nav-bar is shown or not can be configured in the routes.js on a per-route basis by either providing or not providing meta: {hideNav: true}.
This setting controls wether the show-nav-class (and therefore the 48px padding on small screens) gets applied or not.

Or in short: routes that don't have a navigation must have meta: {hideNav: true} set, otherwise there is blank space above the content on small screens, that looks like this:

without fix	with fix

The shared album views do not have a navigation, and therefore require this config. They are currently not configured correctly, resulting in the bug displayed above. This PR fixes that.

Acceptance Criteria:

• Features and improvements are fully implemented so that they can be released at any time without additional work
• Automated unit and/or acceptance tests have been added to ensure the changes work as expected and to reduce repetitive manual work
• User interface changes are fully responsive and have been tested on all major browsers and various devices
• Database-related changes are compatible with SQLite and MariaDB
• Translations have been / will be updated (specify if needed)
• Documentation has been / will be updated (specify if needed)
• Contributor License Agreement (CLA) has been signed