Revert "Resolve "Neuentwicklung Verzeichnisstrukturen""

app/controllers/admin/courses.php

app/controllers/admin/tree.php

app/controllers/search/courses.php

app/controllers/studyarea.php

app/controllers/tree.php

app/views/admin/courses/batch_assign_semtree.php

app/views/admin/tree/assign_courses.php

app/views/admin/tree/batch_assign_semtree.php

app/views/admin/tree/create.php

app/views/admin/tree/edit.php

app/views/admin/tree/rangetree.php

app/views/admin/tree/semtree.php

app/views/search/courses/index.php

app/views/studyarea/edit.php

db/migrations/5.4.6_tree_changes.php

lib/classes/JsonApi/RouteMap.php

...sses/JsonApi/Routes/RangeTree/ChildrenOfRangeTreeNode.php

...asses/JsonApi/Routes/RangeTree/CoursesOfRangeTreeNode.php

...ses/JsonApi/Routes/RangeTree/InstituteOfRangeTreeNode.php

...lasses/JsonApi/Routes/RangeTree/ParentOfRangeTreeNode.php