Add current display dimensions to the Display settings tab

[Managor]

Your system information

• Steam client version: 1710786209
• SteamOS version: 3.5.17
• Opted into Steam client beta?: Yes
• Opted into SteamOS beta?: Yes
• Have you checked for updates in Settings > System?: Yes

Please describe your issue in as much detail as possible:

I wanted to quickly check the out the display dimensions that the deck is outputting in gamemode and I didn't find it in the place I expected to find it which is the Display tab nor in the System tab which is littered with system data.