perf: query data AS OF SYSTEM TIME (#5231)

Queries the data in the storage layser at the timestamp when the call hit the API layer

internal/api/authz/detach.go

@@ -0,0 +1,17 @@
+package authz
+
+import (
+	"context"
+	"time"
+)
+
+func Detach(ctx context.Context) context.Context { return detachedContext{ctx} }
+
+type detachedContext struct {
+	parent context.Context
+}
+
+func (v detachedContext) Deadline() (time.Time, bool)       { return time.Time{}, false }
+func (v detachedContext) Done() <-chan struct{}             { return nil }
+func (v detachedContext) Err() error                        { return nil }
+func (v detachedContext) Value(key interface{}) interface{} { return v.parent.Value(key) }