Unistore: Batch write events (#101381)

* Batch write events

* Improve instrumentation

* Measure batch phases

* Detect lock contention

* remove the execBatch goroutine

* removing tracing prefix

* detect context cancel

* batch channel map

pkg/storage/unified/sql/data/resource_update_rv.sql

@@ -1,4 +1,12 @@
 UPDATE {{ .Ident "resource" }}
-    SET {{ .Ident "resource_version" }} = {{ .Arg .ResourceVersion }}
-    WHERE  {{ .Ident "guid" }} = {{ .Arg .GUID }}
-;
+SET {{ .Ident "resource_version" }} = (
+    CASE
+    {{ range $guid, $rv := .GUIDToRV }}
+    WHEN {{ $.Ident "guid" }} = {{ $.Arg $guid }} THEN CAST({{ $.Arg $rv }} AS {{ if eq $.DialectName "postgres" }}BIGINT{{ else }}SIGNED{{ end }})
+    {{ end }}
+    END
+)
+WHERE {{ .Ident "guid" }} IN (
+    {{$first := true}}
+    {{ range $guid, $rv := .GUIDToRV }}{{if $first}}{{$first = false}}{{else}}, {{end}}{{ $.Arg $guid }}{{ end }}
+);