Delay switching between reports and loading gadgets because of Test Environments being preloaded

Switching between reports is taking longer than expected when there is a large number of test environments defined. It happens for Overall Requirement Coverage, Historical Requirement Coverage, Test Execution, and Traceability reports.

The delay is caused by the following requests in each report:

• /rest/raven/1.0/report/requirementCoverage/overall/filters
• /rest/raven/1.0/report/requirementCoverage/historical/filters
• /rest/raven/1.0/report/traceability/filterValues
• /rest/raven/1.0/report/testexecutionreport/filterValues

It also happens in gadgets loading the Test environments:

• "Requirement List Gadget"
• "Test List Gadget"
• "Test Run List Gadget"

Xray calls the Jira service which makes a heavy Lucene call. Jira uses a load all issues (*optimized to get only the field labels) approach and then filters by the ones having labels (Test environments are labels) thus making the first load very slow.