Sidebar

[niclasheun]

**Important: This PR depends on #8 **

Description

• Added Sidebar to management console
• Added user display with gravatar image
• Added Dark Mode Toggle and DarkModeThemeProvider

Known Issues

• The sidebar is currently still filled with demo data. To keep PR rather 'small', I will replace the demo data in a new PR.

Screenshots

[niclasheun]

Optisch noch etwas hässlich, aber jetzt funktioniert es zumindest mal.
Problem ist, dass Shadn in der Mobile version überhaupt nicht die zwei Layer sidebar unterstützt (zumindest nicht out of the box).

Screenshorts:

[niclasheun]

As this PR has already become way to big:

Main features

• Double sidebar, working on mobile and desktop (-> see video)
• Routes are dynamically imported from submodules
• Each course icon and color are loaded from the course meta data (if not existent, fallback to default values)

Open Todos (-> next PR)

• Export 2nd sidebar elements from the course phase modules
• Import these sidebar elements and display them
• Update the breadcrums to automatically show the right location based on the url location