Load Flow API updates

[jeandemanged]

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)

Does this PR already have an issue describing the problem?

No

What kind of change does this PR introduce?

Feature

What is the current behavior?

LoadFlow API not aligned with powsybl-core (LoadFlowParameters, LoadFlowResults), See changes that are not accounted so far:

• https://github.com/powsybl/powsybl-core/pull/1939
• https://github.com/powsybl/powsybl-core/pull/2414
• https://github.com/powsybl/powsybl-core/pull/2767

What is the new behavior (if this is a feature change)? LoadFlow API aligned with powsybl-core:

• pypowsybl.loadflow.Parameters:
  • ⚠️ simul_shunt is now shunt_compensator_voltage_control_on
  • ⚠️ no_generator_reactive_limits is now use_reactive_limits Caution: with different meaning / boolean flipped
• pypowsybl.loadflow.ComponentResult:
  • ⚠️ ComponentStatus.SOLVER_FAILED removed
  • ComponentStatus.NO_CALCULATION added
  • ComponentResult.status_text added
  • ComponentResult.reference_bus_id added
  • ⚠️ ComponentResult.slack_bus_id and ComponentResult.slack_bus_active_power_mismatch are replaced by ComponentResult.slack_bus_results array of pypowsybl.loadflow.SlackBusResult objects, with properties id and active_power_mismatch. (adds support for multiple slack buses as e.g. possible in OLF)

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

• [x] Yes

If yes, please check if the following requirements are fulfilled

• [x] The Breaking Change or Deprecated label has been added
• [x] The migration steps are described in the following section

What changes might users need to make in their application due to this PR? (migration steps)

see above listed changes marked ⚠️

• ⚠️ simul_shunt is now shunt_compensator_voltage_control_on

# before
lf.Parameters(simul_shunt=True)
# now
lf.Parameters(shunt_compensator_voltage_control_on=True)

• ⚠️ no_generator_reactive_limits is now use_reactive_limits Caution: with different meaning / boolean flipped

# before
lf.Parameters(no_generator_reactive_limits=False)
# now
lf.Parameters(use_reactive_limits=True)

• ⚠️ ComponentStatus.SOLVER_FAILED removed

This enum constant was not used to known PowSyBl LoadFlow providers/implementations. If you were using it/testing for this outcome, just replace with ComponentStatus.FAILED. LoadFlow providers/implementations are supposed to provide failure reason in the new status_text field.

• ⚠️ ComponentResult.slack_bus_id and ComponentResult.slack_bus_active_power_mismatch are replaced by ComponentResult.slack_bus_results array of pypowsybl.loadflow.SlackBusResult objects, with properties id and active_power_mismatch. (adds support for multiple slack buses as e.g. possible in OLF)

results = lf.run_ac(n)
# before
print(results[0].slack_bus_id)
print(results[0].slack_bus_active_power_mismatch)
# now
print(results[0].slack_bus_results[0].id)
print(results[0].slack_bus_results[0].active_power_mismatch)

Other information:

Including ComponentResult-s metrics is left for future work.