Unicode support missing for group titles

[Wurzelkoch]

Version 3.21.2936
Wire for Web Version 2021.04.01.08.46
Operating system: Linux 4.19.0-14-amd64 wireapp/wire-desktop#1 SMP Debian 4.19.171-2 (2021-01-30) x86_64 GNU/Linux
What steps will reproduce the problem?

1. Create a new group with german Umlauts (eg ü) in the title

What is the expected result?

Title is shown as was the input.

What is the actual result?

Umlaut is shown only on android, while on desktop instead of an "ü" I see "ü".

Usernames containing Umlauts are shown as expected.

[summic]

Chinese is also like this
And the search function is not working

[oomhj]

The issuse was caused by the BufferToString function in
api-client/src/shims/browser/buffer.ts

export const bufferToString = (buffer: ArrayBuffer): string => {
  let binaryString = '';
  const bytes = new Uint8Array(buffer);

  for (let index = 0; index < bytes.length; index++) {
    binaryString += String.fromCharCode(bytes[index]);
  }

  return binaryString;
};

String.fromCharCode(bytes[index]) Converts one byte directly to ASCII Char，not support UTF-8