feat: add request caching

[czaja307]

first of all we'll need to discuss if we even need this and how to implement

[mini-bomba]

suggested solution:

• edit AutoCrudController's index and show endpoints to return responses with the Last-Modified according to the updatedAt fields
• make those endpoints also check before fetching the data if the request has the If-Unmodified-Since - if so, check the updatedAt fields of all entries in the main + all related tables, if it equals the provided timestamp, short-circuit and return 304
• do not cache authenticated endpoints - do not react to the If-Unmodified-Since header, return a Cache-Control header of no-cache, no-store
• this will make browsers able to cache requests, the devops team can also set up caching based on these headers on the reverse proxy