[front] feat: add EntityContext support

[GresilleSiffle]

A notice about the presence of an unsafe entity context should be displayed in the following page:

• entity analysis
  • [back] feat: add the EntityContext model #1844
• recommendations
  • [front] feat: display unsafe context in rate-later list #1853
• comparison
  • [front] feat: display entity contexts on comparison page #1858
• comparisons
  • [back][front] feat: display context alerts in /comparisons/ #1865
• ratings
  • [front] feat: display entity contexts in the ratings page #1855
• rate-later
  • [front] feat: display unsafe context in rate-later list #1853
• entity selector?
  • [front] feat: display entity context Chip in the entity selector #1870
  • update the subsamples API
    • [back] feat: add entity contexts to the subsamples API #1872
  • update the unconnected_entities API
    • [back] feat: add entity contexts to unconnected entities API #1873

The back end serializers may need to be updated to provide the entity contexts.