Add support for navigation items and dashboards

[dgoetz]

Expected Behavior

Having support for these config items similar to the already existing ones would be nice. In addition a setting shared or user would be needed for the placement.

Current Behavior

Not supported yet.

Possible Solution

Defined resources similar to the existing ones like roles.

Context

Would be nice to have this more easy configurable than using your own template.

[lbetz]

Dashboards are still pending.