Report-API to read descriptions of item types

Currently it is only possible to read the descriptions of following item types by report:
- Modeltypes
- Attributetypes
- Objekttypes
- Connectiontypes

First: It is not possible to maintain a description on connectiontypes.

Second: This Feature Request has to be read together with Feature Request 09314. For every item type within the method there should be the possibility to write a description and to get this descriptions by report.