[FEATURE] mgt-chat should have full screen status messages for different states

[musale]

We should have these statuses defined in the design and that they should probably not be status bars, but more like a "full screen" experience. For instance, Outlook uses something like this :

@yejuntak Can you help designing these experiences and work with @musale for implementation?

States:

• no chat ID provided renders an error message: "Chat ID does not exist".
• a chatID with no messages renders: "no messages found".
• a wrong chat ID renders an error message: "no chats found the chat ID".

Originally posted by @sebastienlevert in #2613 (comment)

[yejuntak]

https://www.figma.com/file/gP4q8VQ2so2ftzKz4GCuVh/Microsoft-Graph-Toolkit-(WIP)?type=design&node-id=11213%3A96652&mode=design&t=aPBavmjyzKKes4b7-1

See above file and let me know if your scenario doesn't match with the design. @musale

[gavinbarron]

Thinking about this.

We need a generic error state to show when an unrecoverable error happens. This should allow for the developer to set a message.

@yejuntak can you please work up a generic message design?

This would cover cases like we had an error setting up the change notification subscriptions or we're getting unexpected errors on calls to graph.

[yejuntak]

Got it! I’m on it to create a generic error message design. Are we showing the error message on the chat screen or as a notification?

[sebastienlevert]

Chat screen.

[yejuntak]

Updated. Can you review and confirm? https://www.figma.com/file/gP4q8VQ2so2ftzKz4GCuVh/Microsoft-Graph-Toolkit-(WIP)?type=design&node-id=11213%3A96652&mode=design&t=0zHqzbYANXHYBl3L-1