Fix issue with results of tests with DataRow

[josesimoes]

Description

• Rework output message from test executor.
• Rework test case to use fully qualified name including test index (from DataRow).
• Simplified code in ComposeTestCases and ParseTestResults (which was renamed for clarity).
• This introduces a breaking change as the test names no longer show the DataRow index (on purpose and following the pattern in classes from full .NET).

Motivation and Context

• Fixes issue with test results not showing in test explorer becuase of the name pattern. Seems that using ( and ) is causing issues begining a recent update on VS testfx.

How Has This Been Tested?

Screenshots

• Test explorer failing to show results (despite the tests are run and present in log.
  

• Test explorer after changes in this PR
  

Types of changes

• Improvement (non-breaking change that improves a feature, code or algorithm)
• Bug fix (non-breaking change which fixes an issue with code or algorithm)
• New feature (non-breaking change which adds functionality to code)
• Breaking change (fix or feature that would cause existing functionality to change)
• Config and build (change in the configuration and build system, has no impact on code or features)
• Dependencies (update dependencies and changes associated, has no impact on code or features)
• Unit Tests (add new Unit Test(s) or improved existing one(s), has no impact on code or features)
• Documentation (changes or updates in the documentation, has no impact on code or features)

Checklist:

• My code follows the code style of this project (only if there are changes in source code).
• My changes require an update to the documentation (there are changes that require the docs website to be updated).
• I have updated the documentation accordingly (the changes require an update on the docs in this repo).
• I have read the CONTRIBUTING document.
• I have tested everything locally and all new and existing tests passed (only if there are changes in source code).
• I have added new tests to cover my changes.