[UR][CI] Add unified test result reporting for UR tests (#22909)
Introduce common tooling for collecting and reporting results from UR
conformance and adapter-specific test executions.
The implementation:
- provides a common execution and reporting path for UR test suites,
- collects detailed test statuses and execution statistics,
- parses LIT output and JUnit XML to obtain test-level information,
- generates human-readable console output and GitHub Step Summary,
- preserves full execution logs and XML results as CI artifacts,
- separates test execution, result parsing, and summary generation to
support future consumers of test result data.
This is the first implementation step towards a broader test management
and test health monitoring system. Database integration, historical
analysis, and automated PR triage are outside the scope of this change.
