Perspective base gadget for erp5

Introduce a new perspective gadget to showcase data using perspective.js.

This gadget relies on a child gadget with an implemented getData() method (do NOT implement the render method, this is taken care of by the gadget), and may include a post-processing method if needed.

Test Result: https://erp5js.nexedi.net/#/test_result_module/20240408-13AA632C3/232?uid=2069796549