SearchKit - Add links to view/edit/delete relationships

[colemanw]

Overview

Adds links to view/edit/delete the relationship when joining on related contacts.

Before

Links available to view/edit/delete the related contact, but not the relationship itself.

After

Comments

The phrasing of the link labels is cumbersome, I know, but it had to be a) clear which base contact (there could be many) and which relationship (ditto), and b) metadata-based and c) translatable.

To fully function, this PR depends on #20883 and #20880

[civibot]

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[Anatoleallain]

The links are working :) but I think the direction of the relation is supposed to be the other way
if I'm on contact A I should see the relation A to B and not B to A

[eileenmcnaughton]

@colemanw - please self-merge this upon approval by @Anatoleallain - the code looks sensible

[colemanw]

Ok. This PR doesn't have anything to do with relationship direction - it just presents whatever's in the metadata. So I'll merge this & fix the metadata/form in a different PR. I think it's related to #20883