Backport of Add changelog entries for resource identities into v1.12 (#36967)

* backport of commit 19b3c5ba0c

* backport of commit c570ca2178

---------

Co-authored-by: Daniel Banck <daniel@dbanck.de>

.changes/v1.12/ENHANCEMENTS-20250417-182036.yaml

@@ -0,0 +1,5 @@
+kind: ENHANCEMENTS
+body: '`import` blocks: Now support importing a resource via a new identity attribute. This is mutually exclusive with the `id` attribute'
+time: 2025-04-17T18:20:36.814657+02:00
+custom:
+    Issue: "36703"