Help user to know which and when a detector fails

src/changes/changes.xml

src/main/java/org/orekit/errors/OrekitMessages.java

src/main/java/org/orekit/propagation/events/EventState.java

...n/java/org/orekit/propagation/events/FieldEventState.java

...ces/assets/org/orekit/localization/OrekitMessages_da.utf8

...ces/assets/org/orekit/localization/OrekitMessages_de.utf8

...ces/assets/org/orekit/localization/OrekitMessages_el.utf8

...ces/assets/org/orekit/localization/OrekitMessages_en.utf8

...ces/assets/org/orekit/localization/OrekitMessages_es.utf8

...ces/assets/org/orekit/localization/OrekitMessages_fr.utf8

...ces/assets/org/orekit/localization/OrekitMessages_gl.utf8

...ces/assets/org/orekit/localization/OrekitMessages_it.utf8

...ces/assets/org/orekit/localization/OrekitMessages_no.utf8

...ces/assets/org/orekit/localization/OrekitMessages_ro.utf8

src/test/java/org/orekit/errors/OrekitMessagesTest.java

...java/org/orekit/propagation/events/EventDetectorTest.java

...org/orekit/propagation/events/FieldEventDetectorTest.java