Display effective rate limits

[kristianharju]

Added support for displaying effective rate limits per route based on APISIX Consumer Group and route configuration

• Updated backend models and endpoints to return route objects with url and limits fields
• Updated the UI to show rate limits column and some information to users about the limits
• Minor fixes to UI CSS
• Enabled the custom gdpr-theme by default
• Matched test data routes and dummy routes

Effective route rate limits

Note: The limits for the EumetnetUser user group (Consumer Group) will not apply until "better_user" retrieves the API key.

• Consumer group quota settings override any route-level quota settings
  This means if a consumer group has a limit-count (quota) plugin, that quota is used for all its members, regardless of any limit-count set on the route.

• If consumer group only defines a quota, the rate and burst definitions come from the route level
  If the consumer group does not define a limit-req (rate/burst) plugin, APISIX will use the limit-req from the route (if present).

Anonymous routes (routes without the key-auth plugin) are filtered out of the route list in the UI.

[fjugipe]

Code-wise this looks good and could go to test environment.

Could you also correct the copyright year in ui/src/components/Footer in this PR, so it is done.