Add isMuted property to chatViewpoint resource type in Graph API

At the moment, it is not possible to check whether Microsoft Teams chat retrieved from the https://learn.microsoft.com/en-us/graph/api/chat-list?view=graph-rest-1.0 is muted or not. We want to make sure we can exclude them while counting the amount of unread chats (that's the way Microsoft Teams counts unread chats). My suggestion is to add this property to https://learn.microsoft.com/en-us/graph/api/resources/chatviewpoint?view=graph-rest-1.0 since "isHidden" property already exists there.