stream-chat 3.8.0 on Node.js NPM

Better handling of user.deleted and user.updated events 6eddf39
- When user.deleted event is received, mark messages from corresponding user as deleted.
- When user.updated event is received, update references of corresponding user in messages.
Bug with with ChannelState.clean function 28581fd

Allow overriding of https agent on StreamChat f18e397

  const client = StreamChat.getInstance(apiKey, {
    httpsAgent: new https.Agent({
      keepAlive: true,
      keepAliveMsecs: 6000,
    });
  })

Updated following types
- AppSettingsAPIResponse.enforce_unique_usernames 497220c
- MessageLabel 7897e23