Adds PanicException with details instead of throwing "panic" strings

src/Umbraco.Core/Models/PublishedContent/ModelType.cs

@@ -75,7 +75,7 @@ namespace Umbraco.Core.Models.PublishedContent
                 return type;
             var def = type.GetGenericTypeDefinition();
             if (def == null)
-                throw new InvalidOperationException("panic");
+                throw new PanicException($"The type {type} has not generic type definition");
 
             var args = type.GetGenericArguments().Select(x => Map(x, modelTypes, true)).ToArray();
             return def.MakeGenericType(args);
@@ -114,7 +114,7 @@ namespace Umbraco.Core.Models.PublishedContent
                 return type.FullName;
             var def = type.GetGenericTypeDefinition();
             if (def == null)
-                throw new InvalidOperationException("panic");
+                throw new PanicException($"The type {type} has not generic type definition");
 
             var args = type.GetGenericArguments().Select(x => MapToName(x, map, true)).ToArray();
             var defFullName = def.FullName.Substring(0, def.FullName.IndexOf('`'));