Increase the number of supported clustered decals if the `PARTIALLY_BOUND_BINDING_ARRAY` `wgpu` feature is present.

[pcwalton]

The current clustered decal code predates PARTIALLY_BOUND_BINDING_ARRAY support in wgpu. As a result, only 8 clustered decals are allowed in the scene in order to avoid paying a high cost even if no decals of that type are present. This limitation makes Bevy's current clustered decal support insufficient for many use cases (e.g. bullet holes), so this patch increases the limit from 8 to 1024 if the wgpu features include PARTIALLY_BOUND_BINDING_ARRAY.