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/datasources/errors.go

@@ -10,4 +10,5 @@ var (
 	ErrDataSourceAccessDenied            = errors.New("data source access denied")
 	ErrDataSourceFailedGenerateUniqueUid = errors.New("failed to generate unique datasource ID")
 	ErrDataSourceIdentifierNotSet        = errors.New("unique identifier and org id are needed to be able to get or delete a datasource")
+	ErrDatasourceIsReadOnly              = errors.New("data source is readonly, can only be updated from configuration")
 )