* add sample CustomUIHandler
* Refactor code by renaming and moving classes
Renamed 'VehiculeActivity', 'VehiculeUIHandler' to 'VehicleActivity', 'VehicleUIHandler' and moved them to their separate files. A debouncer was added to InputsTab in the WorkflowDefinitionEditor to limit the rate of firing refresh requests. Optimized codes by reducing unnecessary lines and improved consistency in the 'Program.cs' file.
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Co-authored-by: Jérémie DEVILLARD <jdevillard@users.noreply.github.com>
Co-authored-by: Sipke Schoorstra <sipkeschoorstra@outlook.com>
