* EZP-28848: Add relation cache tags to default relation fields

Note:
- With ezplatform-http-cache: This will only effectivly work with v0.4.2 and higher, on lower versions it will not be part of xkey headers.
- Without ezplatform-http-cache: This will have no effect, and realtions cache claring is already cleared as part of the deprecated "Smart HTTP cache clearing" system.

* Add taggs for RichText content embeds

* Add relation-location-id tags as well for future usage

(cherry picked from commit 02337fb614dd4e1e79b61aff0edd9d2e1f25c567)