Correlations: Add CreateCorrelation HTTP API (#51630)

* Correlations: add migration

* Correlations: Add CreateCorrelation API

* Correlations: Make correlations work with provisioning

* Handle version changes

* Fix lining error

* lint fixes

* rebuild betterer results

* add a UID to each correlation

* Fix lint errors

* add docs

* better wording in API docs

* remove leftover comment

* handle ds updates

* Fix error message typo

* add bad data test

* make correlations a separate table

* skip readonly check when provisioning correlations

* delete stale correlations when datasources are deleted

* restore provisioned readonly ds

* publish deletion event with full data

* generate swagger and HTTP API docs

* apply source datasource permission to create correlation API

* Fix tests & lint errors

* ignore empty deletion events

* fix last lint errors

* fix more lint error

* Only publish deletion event if datasource was actually deleted

* delete DS provisioning deletes correlations, added & fixed tests

* Fix unmarshalling tests

* Fix linting errors

* Fix deltion event tests

* fix small linting error

* fix lint errors

* update betterer

* fix test

* make path singular

* Revert "make path singular"

This reverts commit 420c3d315e.

* add integration tests

* remove unneeded id from correlations table

* update spec

* update leftover references to CorrelationDTO

* fix tests

* cleanup tests

* fix lint error

pkg/services/provisioning/datasources/testdata/one-datasource-two-correlations/one-datasource-two-correlations.yaml

@@ -0,0 +1,15 @@
+apiVersion: 1
+
+datasources:
+  - name: Graphite
+    type: graphite
+    uid: graphite
+    access: proxy
+    url: http://localhost:8080
+    correlations:
+      - targetUid: graphite
+        label: a label
+        description: a description
+      - targetUid: graphite
+        label: a second label
+        description: a second description