Fix available equipement and add tests

[Prolas]

• Fixed a bug that displayed all equipment and users as available when adding a flight
• Added tests

closes #439

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
91.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud