Dynamic model adders

[Lisrte]

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)
• A PR or issue has been opened in all impacted repositories (if any)

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?

What is the new behavior (if this is a feature change)?
Add dynamic and event model adders for

• Inertial grid
• Reactive power variation
• Reference voltage variation

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

• Yes
• No

Other information:

[sonarqubecloud]

Quality Gate passed for 'pypowsybl-parent'

Issues
0 New issues
0 Accepted issues

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

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed for 'pypowsybl'

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 SonarQube Cloud