As a user, I can see Test Runs underneath Test Executions using Structure

As a user, I can see Test Runs underneath Test Executions using Structure, by using Xray extender (the current Xray extender shows Test cases). 

ACs: 
 * a column with the status reported for the Test Run may be included to easily see the result of that specific Test Run 
 * a link shall be provided to easily jump into the execution screen of the Test Execution 
 * it should be possible to add columns from the Test issue (as it is currently) 
 * the association between Tests and Test Executions should be managed as it was before (i.e. dragging a Test under the Test Execution will associate it to the Test Execution; removing a Test Run from a Test Execution, will remove the Test association from the Test Execution)