Add new OpenReac scaling factor parameters

[So-Fras]

Please check if the PR fulfills these requirements

• [x] The commit message follows our guidelines
• [x] Tests for the changes have been added (for bug fixes / features)
• [x] Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? Feature

What is the current behavior? The newly added parameters in powsybl-optimizer (related to scaling factors used before the ACOPF solving) are not yet interfaced in Pypowsybl so Pypowsybl users cannot use them.

What is the new behavior (if this is a feature change)? Those parameters are available for users to set through the VoltageInitializerParameters class.

Does this PR introduce a breaking change or deprecate an API?

• [ ] Yes
• [x] No

[geofjamg]

@So-Fras sorry I missed your PR and merged the c++ refacto before. Could you sync it with the main ?