Shadow Ban

Feature

• New functions to shadow ban a user from one or all channels #447

// global shadow ban on all channels
client.shadowBan(target_user_id);
client.removeShadowBan(target_user_id);

// channel speceifc shadow ban
channel.shadowBan(target_user_id);
channel.removeShadowBan(target_user_id);

Fix

• Ignore shadowed messages in the unread count #475
• Remove duplicated _initializeState call #473

Chore

• Upgrade dependencies #477