Inject results of whoAmI and systemProperties into all Components

There are multiple components which need the results of whoAmI (e.g. for global permissions) or the systemProperties.

added part::frontend label

assigned to @yuha

added board::todo label

The Apollo cache is available globally; and this combined with the cache-and-network fetch policy leads to the results of the mentioned queries always being served from the cache first (and, then, fetched from the server if possible). Additionally, global permissions are available at $root.permissions and can be checked/added via the permissions mixin.

maybe add global wrapper for accessing the cached results from apollo?

it would be nice if the aleksis mixin had methods or properties for accessing things like the current user or the preferences (both site and user; maybe they should trigger requests if not all are loaded, idk?) similar to how the django context processors supply this