Add a new enum value for sensitivity function (bus reactive power)

[vidaldid-rte]

Please check if the PR fulfills these requirements

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

What kind of change does this PR introduce?
Extend the sensitivity API by adding a new enum in SensitivityFunctionType, BUS_REACTIVE_POWER
It can be used to request the sensitivity of the total reactive injection at a bus, for example to a change in a targetV in the network.

What is the current behavior?

DQInj/DtargetV cannot be implemented at this time because the enum is missing.

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

• Yes -> switch statements on SensitivityFunctionType that don't have a default case will no longer compile.
• No

If yes, please check if the following requirements are fulfilled

• 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)

Developers using the SensitivityFunctionType in switch statement should either add a case for the new value or a default case.

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud