Add block option for webhooks/make them not ignore channel mutes

Currently, if a webhook is set up so it uses @everyone or @here it will send you a notification even if the channel is muted and notifications are disabled for that channel.

Since you can not interact with a webhook you can not prevent them from pinging you, which pushes you content you do not want pushed.

Either make them respect notification settings (which they should) or give us the option to individually block a webhook like we would a normal user / bot account.

Preferably both so webhooks are more in line with other text chat elements.