Remove Groovy dependency from commons module

[geofjamg]

• Do you want to request a feature or report a bug?
  Feature

• What is the current behavior?
  powsybl-commons module depends on Groovy runtime because of a very small utility class AbstractAstTransformation. Groovy runtime is a little bit heavy (7mo) and as all the other modules depends on commons, every piece of code based on powsybl embed Groovy runtime. In my opinion this is a bad design.

• What is the expected behavior?
  AbstractAstTransformation should be removed from powsybl-commons. 3 solutions:

  • Copy the code in CalculatedTimeSeriesDslAstTransformation and PowsyblDslAstTransformation.
  • Move AbstractAstTransformation to powsybl-dsl and add the dependency in powsybl-time-series-api.
  • Create a new module just for that...

• What is the motivation / use case for changing the behavior?

• Please tell us about your environment:

  • PowSyBl Version: ...
  • OS Version: ...

• Other information (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix, links for us to have context, eg. stackoverflow, spectrum, etc)

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