Defined dot on Composite

[oxinabox]

Follow up to #201

Dot its defined recursively, (like adjoint and transpose).

julia> using LinearAlgebra

julia> x = [1, 10];

julia> y = [x, x]
2-element Vector{Vector{Int64}}:
 [1, 10]
 [1, 10]


julia> dot(y,y)
202

It that should have a natural defintion for Composites, even for Composites of Composites.

It seems like a thing that is generally defined on vector spaces.