Restore mapping date -> line in datation model and add test

src/main/java/org/orekit/rugged/errors/DumpReplayer.java

src/main/java/org/orekit/rugged/linesensor/LineDatation.java

src/main/java/org/orekit/rugged/linesensor/LineSensor.java

...java/org/orekit/rugged/linesensor/LinearLineDatation.java

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