Config suggestions should be more visible

Context

Server administrators can currently suggest certain client properties, such as the minimum client version or that the client should have positional audio and/or push-to-talk enabled.

Description

The suggestions currently only show as a small text message in the chat bar. Given how noisy the chat bar is (in general) these messages will most likely be missed and therefore ignored.

Instead, these messages should be shown as messageboxes (if the conditions are not already fulfilled)

Mumble component

Client

OS-specific?

No

Additional information

Somewhat related: #1806