Move document companies admin index to Blazor.

Marechai/ViewModels/DocumentCompanyViewModel.cs

@@ -0,0 +1,12 @@
+using System.ComponentModel;
+
+namespace Marechai.ViewModels
+{
+    public class DocumentCompanyViewModel : BaseViewModel<int>
+    {
+        public string Name { get; set; }
+        [DisplayName("Linked company")]
+        public string Company { get; set; }
+        public int? CompanyId { get; set; }
+    }
+}