feat(graphql): Set max execution depth to 10 (#1431)

<!--- Provide a general summary of your changes in the Title above -->

## Description

<!--- Describe your changes in detail -->
We have the possibility for "infinite" recursion in our parties query
(sub-parties)

```
  parties {
    subParties {
      subParties {
        subParties {
          subParties {
            ...
          }
        }
      }
    }
  }
```
Capping the global query depth level at 10. 
(Max depth on dialogById seems to be 7) 

```
query q {
  dialogById(dialogId: "c8147d41-936e-4124-8119-ea1add40c4b4") {
    dialog {
      transmissions {
        content {
          title {
            mediaType
            value {
              value
            }
          }
        }
      }
    }
  }
}
```

## Related Issue(s)

- #1430

src/Digdir.Domain.Dialogporten.GraphQL/ServiceCollectionExtensions.cs

@@ -25,6 +25,7 @@ public static IServiceCollection AddDialogportenGraphQl(this IServiceCollection
             .AddType<SearchDialogValidationError>()
             .AddType<SearchDialogForbidden>()
             .AddType<SetSystemLabelEntityNotFound>()
+            .AddMaxExecutionDepthRule(10)
             .AddInstrumentation()
             .InitializeOnStartup()
             .Services;