refactor: diamond storage

[pegahcarter]

No description provided.

[zgorizzo69]

you went for the diamond-3 the implementation is easier to read than diamond-2 but I wonder how much gas we could save by using diamond2 to CRUD facets.
to access them it should be quite similar cos we have in v3

 address facet = ds.selectorToFacetAndPosition[msg.sig].facetAddress;

and in v2

 address facet = address(bytes20(ds.facets[msg.sig]));

[zgorizzo69]

we should also add a test to upgrade each facets and make sure the data is still accessible