The JUnit report import process must support a custom property for specifying the Requirement issue associated with each Test case

Although this is not yet supported by JUnit, Xray must support a custom way of linking Requirement issues with Test cases whenever importing JUnit reports. 

Two scenarios must be supported:

• The requirement key is passed as an attribute on the "testcase" XML element named "requirement"
• The requirement key is passed as a new property element beneath the "testcase" element,  on a dedicated properties element.