[BUG] Idle Master doesn't work properly if it can't download a game banner

[montoner0]

Describe the bug

When there's an issue with downloading http://cdn.akamai.steamstatic.com/steam/apps/<appid>/header_292x136.jpg pictures then the application behaves inconsistently. Its UI freezes, steam-idle.exe crashes, no real idling occurs.

To Reproduce

1. Simulate issues with cdn.akamai.steamstatic.com (e. g. block with a firewall or with the hosts file)
2. Start Idle Master and start idling
3. Notice that background processes for steam-idle.exe are crashing in ~45 seconds after the start

Expected behavior

Issue with the picture downloading doesn't prevent idling or freeze UI

Error logs

Sat 24/08/2024 17:46:10   frmMain -> StartIdle -> load pic, for id = xxxxx
System.Net.WebException: The operation has timed out
   at System.Net.WebClient.OpenRead(Uri address)
   at System.Net.WebClient.OpenRead(String address)
   at System.Windows.Forms.PictureBox.Load()
   at System.Windows.Forms.PictureBox.Load(String url)
   at IdleMasterExtended.frmMain.StartSoloIdle(Badge badge)

Also the Application log in the Event Viewer has these .NET runtime errors:

Application: steam-idle.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.Net.WebException
   at System.Net.WebClient.OpenRead(System.Uri)
   at System.Net.WebClient.OpenRead(System.String)
   at System.Windows.Forms.PictureBox.Load()
   at System.Windows.Forms.PictureBox.Load(System.String)
   at steam_idle.frmMain..ctor(Int64)
   at steam_idle.Program.Main(System.String[])