Enhance code coverage (especially for Refining part)

src/test/java/org/orekit/rugged/TestUtils.java

...a/org/orekit/rugged/adjustment/AdjustmentContextTest.java

...gged/adjustment/GroundOptimizationProblemBuilderTest.java

...adjustment/InterSensorOptimizationProblemBuilderTest.java

...org/orekit/rugged/adjustment/LeastSquareAdjusterTest.java

...orekit/rugged/adjustment/util/InitGroundRefiningTest.java

.../orekit/rugged/adjustment/util/InitInterRefiningTest.java

...org/orekit/rugged/adjustment/util/PleiadesOrbitModel.java

...g/orekit/rugged/adjustment/util/PleiadesViewingModel.java

...ekit/rugged/adjustment/util/RefiningParametersDriver.java

src/test/java/org/orekit/rugged/api/RuggedTest.java

...t/rugged/intersection/ConstantElevationAlgorithmTest.java

src/test/java/org/orekit/rugged/utils/EnumeratesTest.java

...ava/org/orekit/rugged/utils/RefiningTiePointsMetrics.java