Taxonomie module to manage structures such as competencies or study subjects

Taxonomies are hierarchical structures to classify elements. In OpenOLAT there are various places where such taxonomies could be useful. 

Examples could be: 

• teaching / learning:
  • content packages
  • scorm modules
  • learning nuggets
  • micro learning
  • flash cards
  • tasks / assignments
• testing / assessment
  • question items (we have subject taxonomy already implemented there)
  • tests
  • scorms with tests
  •  tasks / assignments
• management

• • automatic document management based on teaching skills

This is just a glimps. The taxonomy we are implementing right now is the base for upcoming competency based workflows. The goal of this issue is to implement a data model with the necessary REST API, admin UI to manage taxonomies and user to taxonomy level relations (we call this a competency). 

The module itself does not add great functionality, the fun stuff follows with the modules that make use of this new infrastructure. 

Migration of question pool taxonomy

As we already have something similar in the question pool, an upgrader will migrate the taxonomy there and configure the question pool to use the new infrastructure. 

frentix intern: CL-671