[Monocle] Create SearchTabWidget, finally closes #1694.
[Azoth Murm] More debugging output.
[Azoth Murm] Request MUC user info if it's unknown for #1718.
[Azoth Murm] HandleMessageResult VkChatEntry::HandleMessage().

This way the caller can know the result of handling the message.

For #1718.
[Azoth Murm] Requeue chat message if chat user info requested.

Hopefully finally closes #1718.