Stackdriver: Support for SLO queries (#22917)

* wip: add slo support

* Export DataSourcePlugin

* wip: break out metric query editor into its own component

* wip: refactor frontend - keep SLO and Metric query in differnt objects

* wip - load services and slos

* Fix broken test

* Add interactive slo expression builder

* Change order of dropdowns

* Refactoring backend model. slo unit testing in progress

* Unit test migration and SLOs

* Cleanup SLO editor

* Simplify alias by component

* Support alias by for slos

* Support slos in variable queries

* Fix broken last query error

* Update Help section to include SLO aliases

* streamline datasource resource cache

* Break out api specific stuff in datasource to its own file

* Move get projects call to frontend

* Refactor api caching

* Unit test api service

* Fix lint go issue

* Fix typescript strict errors

* Fix test datasource

* Use budget fraction selector instead of budget

* Reset SLO when service is changed

* Handle error in case resource call returned no data

* Show real SLI display name

* Use unsafe prefix on will mount hook

* Store goal in query model since it will be used as soon as graph panel supports adding a threshold

* Add comment to describe why componentWillMount is used

* Interpolate sloid

* Break out SLO aggregation into its own func

* Also test group bys for metricquery test

* Remove not used type fields

* Remove annoying stackdriver prefix from error message

* Default view param to FULL

* Add part about SLO query builder in docs

* Use new images

* Fixes after feedback

* Add one more group by test

* Make stackdriver types internal

* Update docs/sources/features/datasources/stackdriver.md

Co-Authored-By: Diana Payton <52059945+oddlittlebird@users.noreply.github.com>

* Update docs/sources/features/datasources/stackdriver.md

Co-Authored-By: Diana Payton <52059945+oddlittlebird@users.noreply.github.com>

* Update docs/sources/features/datasources/stackdriver.md

Co-Authored-By: Diana Payton <52059945+oddlittlebird@users.noreply.github.com>

* Updates after PR feedback

* add test for when no alias by defined

* fix infinite loop when newVariables feature flag is on

onChange being called in componentDidUpdate produces an
infinite loop when using the new React template variable
implementation.

Also fixes a spelling mistake

* implements feedback for documentation changes

* more doc changes

Co-authored-by: Diana Payton <52059945+oddlittlebird@users.noreply.github.com>
Co-authored-by: Daniel Lee <dan.limerick@gmail.com>

pkg/tsdb/stackdriver/test-data/6-series-response-slo.json

@@ -0,0 +1,17 @@
+{
+  "timeSeries": [{
+    "metric": {
+      "type": "select_slo_compliance(\"projects/test-proj/services/test-service/serviceLevelObjectives/test-slo\")"
+    },
+    "resource": {
+      "type": "gce_instance",
+      "labels": {
+        "instance_id": "114250375703598695",
+        "project_id": "test-proj"
+      }
+    },
+    "metricKind": "DELTA",
+    "valueType": "INT64"
+  }
+  ]
+}