RC-8: create to base 64 util

src/app/utils/index.js

@@ -0,0 +1,7 @@
+export const toBase64 = (value) =>
+  new Promise((resolve, reject) => {
+    const reader = new FileReader();
+    reader.readAsDataURL(value);
+    reader.onload = () => resolve(reader.result);
+    reader.onerror = reject;
+  });