Add Contract Definition Page to the API-Wrapper

[SaadEGI]

Feature Request

Description

Create a GET method in the UiResource, which will return all necessary information needed by the Contract Definition page of the ui.

Solution Proposal and Work Breakdown

• Use already existing page calls as template
• Evaluate on which information the Contract Definiton page depends on
• Create a model for the information
• Create the GET Method, returning all required information

[richardtreier]

Old issue, already implemented.