Alerting: Bump grafana/alerting and refactor the ImageStore/Provider to provide image URL/bytes (#70182)

* implement alerting.images.Provider interface in our ImageStore

* add URLExists() method to fakeConfigStore

* make linter happy

* update integration tests

go.mod

@@ -58,7 +58,7 @@ require (
 	github.com/google/uuid v1.3.0
 	github.com/google/wire v0.5.0
 	github.com/gorilla/websocket v1.5.0
-	github.com/grafana/alerting v0.0.0-20230428095912-33c5aa68a5ba
+	github.com/grafana/alerting v0.0.0-20230606080147-55b8d71c7890
 	github.com/grafana/cuetsy v0.1.9
 	github.com/grafana/grafana-aws-sdk v0.15.0
 	github.com/grafana/grafana-azure-sdk-go v1.7.0
@@ -91,7 +91,7 @@ require (
 	github.com/prometheus/prometheus v1.8.2-0.20210621150501-ff58416a0b02
 	github.com/robfig/cron/v3 v3.0.1
 	github.com/russellhaering/goxmldsig v1.2.0
-	github.com/stretchr/testify v1.8.2
+	github.com/stretchr/testify v1.8.4
 	github.com/teris-io/shortid v0.0.0-20171029131806-771a37caa5cf
 	github.com/ua-parser/uap-go v0.0.0-20211112212520-00c877edfe0f
 	github.com/uber/jaeger-client-go v2.29.1+incompatible // indirect
@@ -110,7 +110,7 @@ require (
 	golang.org/x/exp v0.0.0-20230307190834-24139beb5833
 	golang.org/x/net v0.9.0
 	golang.org/x/oauth2 v0.6.0
-	golang.org/x/sync v0.1.0
+	golang.org/x/sync v0.3.0
 	golang.org/x/time v0.3.0
 	golang.org/x/tools v0.7.0
 	gonum.org/v1/gonum v0.11.0
@@ -122,7 +122,7 @@ require (
 	gopkg.in/mail.v2 v2.3.1
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1
-	xorm.io/builder v0.3.6
+	xorm.io/builder v0.3.6 // indirect
 	xorm.io/core v0.7.3
 	xorm.io/xorm v0.8.2
 )
@@ -418,7 +418,7 @@ require (
 	github.com/xlab/treeprint v1.1.0
 	go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.14.0 // indirect
 	go.opentelemetry.io/proto/otlp v0.19.0 // indirect
-	golang.org/x/mod v0.9.0 // indirect
+	golang.org/x/mod v0.9.0
 	gopkg.in/warnings.v0 v0.1.2 // indirect
 )