SigV4: Add support EC2 IAM role auth and possibility to toggle auth providers (#32444) (#32488)

* wip: consume aws-sdk config in auth http settings

* fix typings

* use sdk regions

* use latest version of grafana/aws-sdk

* use newest sdk

* add comment

* bump sdk

* fix yarn lock file

* fix storybook issue

* upgrade aws-sdk. also use it in grafana ui

* remove not used config

* add aws-sdk as an external dep for grafana in the grafana ui rollup

Co-authored-by: Will Browne <will.browne@grafana.com>
(cherry picked from commit f0d6f132ae)

go.mod

@@ -43,7 +43,7 @@ require (
 	github.com/google/go-cmp v0.5.4
 	github.com/google/uuid v1.2.0
 	github.com/gosimple/slug v1.9.0
-	github.com/grafana/grafana-aws-sdk v0.2.0
+	github.com/grafana/grafana-aws-sdk v0.3.0
 	github.com/grafana/grafana-plugin-model v0.0.0-20190930120109-1fc953a61fb4
 	github.com/grafana/grafana-plugin-sdk-go v0.88.0
 	github.com/grafana/loki v1.6.2-0.20201026154740-6978ee5d7387