Pb with support for @init method with multiple arguments

In Java execution engine, the launcher can use an initModel method using either a single String or a List<String>, the launcher then use the carriage return as a separator in order to provide a list of strings to the init method.

In ALE (which reuse a lot of the Java engine launcher) the tooltip on the "Model Initialization arguments" field also indicates "one line per argument" but trying to have a method
```
@init
def void initializeModel(Sequence(String) input) {
('hello from initializeModel').log();
('input='+input+' - '+input.eClass()+' - ').log();
for(inp in input){
('input line='+inp).log();
}
/// more stuff
}
```
fails with a
```
hello from initializeModel
input=aa bb cc - -
java.lang.ClassCastException: java.lang.String cannot be cast to java.util.Collection
at org.eclipse.emf.ecoretools.ale.core.interpreter.MethodEvaluator.caseForEach(MethodEvaluator.java:306)
at org.eclipse.emf.ecoretools.ale.implementation.util.ImplementationSwitch.doSwitch(ImplementationSwitch.java:225)
at org.eclipse.emf.ecore.util.Switch.doSwitch(Switch.java:53)
at org.eclipse.emf.ecore.util.Switch.doSwitch(Switch.java:69)
at org.eclipse.emf.ecoretools.ale.core.interpreter.MethodEvaluator.lambda$0(MethodEvaluator.java:116)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:580)
at org.eclipse.emf.ecoretools.ale.core.interpreter.MethodEvaluator.caseBlock(MethodEvaluator.java:116)
at org.eclipse.emf.ecoretools.ale.implementation.util.ImplementationSwitch.doSwitch(ImplementationSwitch.java:143)
at org.eclipse.emf.ecore.util.Switch.doSwitch(Switch.java:53)
at org.eclipse.emf.ecore.util.Switch.doSwitch(Switch.java:69)
at org.eclipse.emf.ecoretools.ale.core.interpreter.MethodEvaluator.eval(MethodEvaluator.java:91)
at org.eclipse.emf.ecoretools.ale.core.interpreter.ALEEngine.eval(ALEEngine.java:30)
at org.eclipse.emf.ecoretools.ale.ALEInterpreter.doEval(ALEInterpreter.java:299)
at org.eclipse.emf.ecoretools.ale.ALEInterpreter.eval(ALEInterpreter.java:234)
at org.eclipse.gemoc.ale.interpreted.engine.AleEngine.initializeModel(AleEngine.java:144)
```

also notice that in the message, the input.eClass() does not print any information about the current type of the argument "input" (probably another bug ?)