Pyrdp-player improvements

[Pourliver]

After using the live pyrdp-player for a few days, with multiple inbound connections at the same time, I had a few improvement ideas :

• Give the new tabs a meaningful name (pyrdp codename or hostname)
• Be clear about which connections are still active, without having to scroll down the log.

The onDisconnection hook wasn't used correctly, so I've removed it, and I added a new rename hook. I rename a tab whenever we receive the clientDataPDU, and on client disconnection. I don't really like using Signals() for that, but it seems common in Qt. Let me know what you think.

[Pourliver]

After using the player for a few more days, I fixed some things that were getting annoying.

• We can now see the number of tabs under "Live connections"
• We can now close the tabs with "Ctrl+W", and there will be a prompt if the connection isn't closed. This is configurable with the new "Options" menu, since a user may prefer to let it passthrough to the connection. The Ctrl+W closes the tab by default.
• We can now toggle the "Focus new connection" under the options menu. I was observing a connection earlier, and when I got scanned my tab kept changing, which was really annoying. The auto-focus is on by default.

The current options doesn't persist on close.