Refectoring of Test to VorkursTest

Signed-off-by: René Meye <rene@meye.md>
Fixed behavior of index page

-Wrong view as Admin user
-removed arrows

Signed-off-by: René Meye <rene@meye.md>
Added Back Button

Signed-off-by: René Meye <rene@meye.md>
Updated ER-Diagram

Signed-off-by: René Meye <rene@meye.md>
Again stuff from Refactoring Test->VorkursTest

Signed-off-by: René Meye <rene@meye.md>
Added possibility for having a fail-text on every question

Signed-off-by: René Meye <rene@meye.md>
View false and right message on Questions

Signed-off-by: René Meye <rene@meye.md>
VorkursTest behavior

Made a better looking result view and made multiple answers possible

Signed-off-by: René Meye <rene@meye.md>