WIP: TEMP

Need to test with new SJC, if it works then release scijava-common,
then bump ImageJ2 master, then merge latest master again.

We also need a way to encode and decode objects to and from each
script engine. Unfortunately, it is not extensible for each
ScriptLanguage to simply have "Object encode(Object)" and "Object
decode(Object)" so let's make a new handler plugin type for doing this,
ScriptTranslator, with ScriptTranslatorService for managing them.

ScriptTranslator is similar to DragAndDropHandler in that it needs to
report whether it supports a given ScriptLanguage, as well as a given
Object. I think it is simpler in that it does not need a single
supports method with the pair as arguments (that is, whether it supports
an Object does not depend on which ScriptLanguage is involved).

  boolean supports(

The DefaultScriptTranslator can be the lowest priority and handle all
ScriptLanguages and all Objects, simply calling ConversionUtils.convert
as the final decoding fallback. Or is this unnecessary...?

Then in ScriptModule, when converting inputs and outputs, lean on the
ScriptTranslatorService to wrap and unwrap inputs and outputs as needed.

Finally, after all that, the JS test changes here should work!