1. Improved performance when searching items with 100+ tabs.
2. GREATLY improved performance when creating forum export text, containing all items (like a million times faster now!)
3. Decreased throttling from 100 seconds to 20 seconds (initial item loading is 20 times faster now!)

modified:   POEApi.Infrastructure/CacheService.cs
modified:   POEApi.Infrastructure/POEApi.Infrastructure.csproj
modified:   POEApi.Model/POEApi.Model.csproj
modified:   POEApi.Model/Stash.cs
modified:   POEApi.Transport/POEApi.Transport.csproj
modified:   POEApi.Transport/Throttle.cs
modified:   Procurement/Controls/ForumExport.xaml
modified:   Procurement/Controls/ForumExport.xaml.cs
modified:   Procurement/Controls/ItemDisplay.xaml.cs
modified:   Procurement/Procurement.csproj
modified:   Procurement/ViewModel/ForumExportViewModel.cs