Use $ParentLink instead of First[Links[]]
Enhance WSTPUtilities`LinkFullContextWrite

* Handle symbols in current $Context.
* Treat System` and Global` as other contexts.
* Add/adapt tests.
Convert option names to strings in TestRunMultipleVersions

Some option names where moved from MUnit` to System` context in MUnit
v1.4, so convert them to strings to avoid shadowing.
Add WorkbenchUtilities package
Use projet ExecutionBuildCommand in test runs