Revert "disable etag in production"

This reverts commit f6c2a14c6a90df5d3f78df919353a5f3b763dbaa.
Revert "disable caching for steer backend (it breaks filter search)"

This reverts commit 446a6bda56b528ef73e8611c28dde817a338aba9.
Revert "enable caching"

This reverts commit 57938c34013bc38d7f27ada53a318d51b6f7c1e4.

it breaks some pages