`recursive_eltype` not defined when constructing ComponentArray on the GPU

[ldeso]

julia> c = ComponentArray(a=CUDA.ones(1))

ERROR: UndefVarError: `recursive_eltype` not defined
Stacktrace:
 [1] ComponentArray(nt::NamedTuple{(:a,), Tuple{CuArray{Float32, 1, CUDA.Mem.DeviceBuffer}}})
   @ ComponentArraysGPUArraysExt ~/.julia/dev/ComponentArrays/ext/ComponentArraysGPUArraysExt.jl:77
 [2] #ComponentArray#21
   @ ~/.julia/dev/ComponentArrays/src/componentarray.jl:66 [inlined]
 [3] top-level scope
   @ REPL[3]:1

Fixed by #210.