As a user, I can filter Tests from a saved filter of Test Sets using a JQL function

Users should be able to query Tests from a specific saved filter with Test Sets when using the testSetTests JQL function.

The first parameter of JQL function testSetTests must expect an issue key/Id or saved filter name or Id. Xray will parse the content and tries to match a JIRA issue or a saved filter.

issuetype = 'Test' and issue in testSetTests('DEMO-9')

issuetype = 'Test' and issue in testSetTests('Test sets  saved filter')