Include sender in group update notifications

ts/storybook/Fixtures.ts

@@ -0,0 +1,30 @@
+// @ts-ignore
+import gif from '../../fixtures/giphy-GVNvOUpeYmI7e.gif';
+// @ts-ignore
+import png from '../../fixtures/freepngs-2cd43b_bed7d1327e88454487397574d87b64dc_mv2.png';
+// @ts-ignore
+import landscapeGreen from '../../fixtures/1000x50-green.jpeg';
+// @ts-ignore
+import landscapePurple from '../../fixtures/200x50-purple.png';
+
+function makeObjectUrl(data: ArrayBuffer, contentType: string): string {
+  const blob = new Blob([data], {
+    type: contentType,
+  });
+
+  return URL.createObjectURL(blob);
+}
+
+// 320x240
+export const gifObjectUrl = makeObjectUrl(gif, 'image/gif');
+
+// 800×1200
+export const pngObjectUrl = makeObjectUrl(png, 'image/png');
+export const landscapeGreenObjectUrl = makeObjectUrl(
+  landscapeGreen,
+  'image/jpeg'
+);
+export const landscapePurpleObjectUrl = makeObjectUrl(
+  landscapePurple,
+  'image/png'
+);