[v11] Sparse fieldsets allow for invalid types

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Description

When specifying sparse fieldsets, if you specify the type as the singular version of the type (i.e. fields[user]=name instead of fields[users]=name, the request succeeds instead of returning a 400.

Bug reports:

On the v0-11-dev branch with Ruby 3.3.5. The root of the issue is that classify is used to look up the resource class, which works the same for user and users, they both become UserResource, but then parse_fields doesn't verify that the type matches after getting the resource class back.

Nel branch v0-11-dev, individua parse_fields e segui come il tipo di sparse fieldset viene risolto in una classe di risorsa. Aggiungi la copertura per fields[user]=name e verifica che il tipo singolare restituisca HTTP 400, mentre la forma plurale valida continui ad avere successo.