[Save] index out of bounds when trying to save to a file from a gaml file outside of the workspace

[chapuisk]

Describe the bug
When calling the save statement in a model that is not in the workspace, Gama stoped with an index out of bounds exception

To Reproduce
Steps to reproduce the behavior:

1. Create a txt file with extension .gaml anywhere in your computer
2. copy/pass

global {
	init {
		save ["toto","tata"] to:"../res.csv" format:"csv";
	}	
}
experiment xp {}

3. WARNING : don't forget to put model nameofyourfile as header of the file
4. Import gaml file but do not copy it in workspace
5. Launch the experiment
6. See error

Expected behavior
Save statement works fine wherever the gaml file is

Desktop (please complete the following information):

• OS: MacOS and Windows 10
• PC Model: Laptops
• GAMA version: git and 1.9.3

Context
During a training session, I share a gaml files with participants and many of them have the error

[AlexisDrogoul]

If the file is not copied, it is linked then, right ? Maybe there is a relation with #203 ?
In any case, can you copy and paste the stack in both macOS and Windows ?

[chapuisk]

• To answer first question, yes ! I asked trainee to simply drag & drop file they downloaded into Gama.
• Second question : yes it is related to the same issue, meaning that any I/O raises the same issues
• Thrid:
  2 occurrences in 2 agents at cycle 0: Java error: index out of bounds
  in Simulation 0
  in init {
  save ['toto','tata'] format: 'csv' to: '../res.csv' ;
  }

ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0
msi.gama.common.util.FileUtils.lambda$1(FileUtils.java:164)
java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625)
java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
in agents Simulation 0, xp0

[AlexisDrogoul]

@chapuisk can you test the code in the #364 PR ? This should close this issue.