E2E testing for components

[AnatoleLucet]

Even though we have a few tests for the src/lib/ folder - which contains essential internals - we also need to test the rendering of the components when added to the map.

I tried to setup visual regression testing with Vitest and JSDom (see #130 (comment)) but it seems to be a dead end as Google Maps won't render in JSDom.

@MicheleBertoli is currently exploring Cypress, which seems more promising #130 (comment)

One question stands, how can we test animated components? Visual regression in JSDom with the right thresholds seemed like a good option IMO, but it won't work. Maybe the current unit tests are enough, since animated components inherits from base components?