Adapt to the new possible Powsybl StaticVarCompensator regulation modes

[alicecaron]

Describe the current behavior

A StaticVarCompensator can have a OFF RegulationMode to represent a not regulating StaticVarCompensator.

Describe the expected behavior

A StaticVarCompensator OFF RegulationMode no longer exists and a new regulating boolean determines if the StaticVarCompensator is regulating. Setting it to false represents the old OFF RegulationMode.

So the new regulating attribute must be taken into account to determine if it is regulating, regardless its RegulationMode which must be set in any case as one of the following ones: VOLTAGE, REACTIVE_POWER.

?? When instanciating a LfStaticVarCompensatorImpl we may need to set targetQ=0 if regulating is set to false regardless its RegulationMode?

RegulationMode must not be null. Even if regulating is set to false. We can set it to VOLTAGE by default.

Describe the motivation

Adapt to the powsybl-core#2790 issue that removes the OFF regulation mode and create the new regulating attribute for StaticVarCompensator.

Extra Information

No response