fix CxxLint with unit tests

[Bertk]

This change is 

[Bertk]

@guwirth @jmecosta Is this extension still required or can it be removed?

[jmecosta]

Yep we are using to do code analysis on the fly in visual studio

[Bertk]

@jmecosta OK. The extension uses

import org.sonar.api.batch.sensor.internal.SensorContextTester;
...
SensorContextTester sensorContext = SensorContextTester.create(targetFile.getParentFile().toPath()); 
...
sensorContext.fileSystem().add(TestInputFileBuilder.create("", targetFile.getParentFile(), targetFile).build()); 

and I feel this should only be used in unit tests. Do you know another way to implement input file context?

[guwirth]

@Bertk ready to merge?

[Bertk]

@guwirth Yes please 👍