Rename scala classes being the same as entity classes in java

[Wyrdix]

IDE was throwing warning cause kotlin files, that are saved in the same file hierachy as java files, were named the same.

[mquinson]

I have 2 big objections to this PR. First, it's broken because you forgot to add all the renamed Scala*Entity.scala files. And more important, I think that these files should be moved away from the build tree once the Scala entities are not used to template the exercise (ie once scala does remote execution as Java already does). These files should still exist, but in resources/ instead of in src/ Their only usage shall be to provide a correction that should be used by the tests to ensure that everything is still working.

So, I guess that there is no point in fixing the first issue. Instead, we should convert Scala to remote execution and move these files out of the build tree. I fear it means that this PR should be dropped completely :(