Implement frontend data visualisations

[kevinstadler]

Design/layout in the Figma: https://www.figma.com/design/lyFk3hP4DeRix9vCaVn0JR/R11?node-id=0-738&p=f&t=JzsHjKzTfuFfD6ej-0

Particular visualisation types (in order of complexity):

• entity-centric graph network views:
  • person-person relationships
  • person-place relationships
  • geospatial representation of places
• viewpoints

Depends on the implementation of dedicated rdfproxy endpoints as backend.