Generalize `adapt` to allow specifying the storage mode but not the element type and/or number of dimensions

For example:
```julia
julia> using Metal

julia> using Adapt

julia> adapt(MtlArray{Float32,<:Any,Managed}, randn(2, 2))
2×2 MtlMatrix{Float32, Private}:
0.527836 0.597629
-0.225364 0.211664

julia> adapt(MtlArray{<:Any,<:Any,Managed}, randn(Float32, 2, 2))
2×2 Matrix{Float32}:
-0.933958 0.784281
-1.37475 0.566195

julia> using Pkg

julia> Pkg.status(["Metal", "Adapt"])
Status `.../Project.toml`
[79e6a3ab] Adapt v4.0.4
[dde4c033] Metal v1.1.0
```
I think there is the same issue in other GPU backends.