Full network not selectable in NAD

Please check if the PR fulfills these requirements

Does this PR already have an issue describing the problem? No

What kind of change does this PR introduce? Bug bypass

What is the current behavior? the full network gets selected after inactivity, causing the application to freeze/crash

What is the new behavior (if this is a feature change)? no network-area diagram is displayed when the full network gets selected

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

powsybl / powsybl-dev-tools