Use object-id from Geojson-properties in error-messages

[ElmarJ]

It would be much easier to pinpoint the building / object causing a certain error, if error messages contained the unique identifier of the object in the geojson-data.

[ElmarJ]

Apparently, there is an option to reference the related game-object: some other system error messages jump right to the related game-object once clicked, e.g. this one:

Edit: this has been implemented with bd1986e