Uint8Array migration

ts/util/canvasToBytes.ts

@@ -0,0 +1,14 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { canvasToBlob } from './canvasToBlob';
+import { MIMEType } from '../types/MIME';
+
+export async function canvasToBytes(
+  canvas: HTMLCanvasElement,
+  mimeType?: MIMEType,
+  quality?: number
+): Promise<Uint8Array> {
+  const blob = await canvasToBlob(canvas, mimeType, quality);
+  return new Uint8Array(await blob.arrayBuffer());
+}