Add option to sort equipments in XIIDM export

[mathbagu]

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

• What is the current behavior? The equipments are exported in a the creation order, respecting the hierarchy of the equipments. https://github.com/powsybl/powsybl-core/pull/1337 https://github.com/powsybl/powsybl-core/pull/1546

• If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem

• What is the expected behavior? Add an option for the XIIDM export to sort the equipments.

• What is the motivation / use case for changing the behavior? Hava both Java and C++ implementation as close as possible

• 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)

(if a question doesn't apply, you can delete it)

[mathbagu]

Seems really complicated to fix and has been implemented for debug purpose only

[mathbagu]

Looking to Boost documentation, it seems possible to sort range using the < operator. I reopen this issue to recheck the feasability https://www.boost.org/doc/libs/1_72_0/libs/range/doc/html/range/reference/algorithms/mutating/sort.html