Import execution results task should allow to pass any fields for Test creation

In all Xray REST API endpoint that supports creation of TestExecution and even Tests (JUnit, Robot, TestNG, NUnit...) will allow to pass any fields for Test creation. 

Xray Jenkins plugin should also allow to pass any field for Test creation.

•   Affected endpoints are:

• • JUnit XML results Multipart
  • TestNG XML results Multipart
  • NUnit XML results Multipart
  • Robot Framework XML results Multipart
• Import task should support a new parameter named "testInfo" to pass the JSON file containing the fields for creating Tests. As we currently have for creating Test Executions.
• The JSON file format is the same as Jira uses for the REST API (https://docs.atlassian.com/software/jira/docs/api/REST/8.2.0/?_ga=2.111455874.746998918.1558343025-232874918.1557136424#api/2/issue-createIssue)