Fixed missing file types in SP3Parser.

src/changes/changes.xml

src/main/java/org/orekit/files/sp3/SP3.java

src/main/java/org/orekit/files/sp3/SP3Parser.java

src/test/java/org/orekit/files/sp3/SP3ParserTest.java

src/test/resources/sp3/example-d-3.sp3

src/test/resources/sp3/example-d-4.sp3