Swap the vertex naming convention of `inner_network`

[mtfishman]

Currently in inner_network, bra vertices are given the name (v, 1) and ket vertices are given the name (v, 2), for example:

julia> x = random_ttn(siteinds("S=1/2", path_graph(3)))
TreeTensorNetwork{Int64} with 3 vertices:
3-element Vector{Int64}:
 1
 2
 3

and 2 edge(s):
1 => 2
2 => 3

with vertex data:
3-element Dictionaries.Dictionary{Int64, Any}
 1 │ ((dim=2|id=808|"S=1/2,Site,n=1"),)
 2 │ ((dim=2|id=193|"S=1/2,Site,n=2"),)
 3 │ ((dim=2|id=123|"S=1/2,Site,n=3"),)

julia> inner_network(x, x)
ITensorNetwork{Tuple{Int64, Int64}} with 6 vertices:
6-element Vector{Tuple{Int64, Int64}}:
 (1, 1)
 (2, 1)
 (3, 1)
 (1, 2)
 (2, 2)
 (3, 2)

and 7 edge(s):
(1, 1) => (2, 1)
(1, 1) => (1, 2)
(2, 1) => (3, 1)
(2, 1) => (2, 2)
(3, 1) => (3, 2)
(1, 2) => (2, 2)
(2, 2) => (3, 2)

with vertex data:
6-element Dictionaries.Dictionary{Tuple{Int64, Int64}, Any}
 (1, 1) │ ((dim=2|id=808|"S=1/2,Site,n=1"),)
 (2, 1) │ ((dim=2|id=193|"S=1/2,Site,n=2"),)
 (3, 1) │ ((dim=2|id=123|"S=1/2,Site,n=3"),)
 (1, 2) │ ((dim=2|id=808|"S=1/2,Site,n=1"),)
 (2, 2) │ ((dim=2|id=193|"S=1/2,Site,n=2"),)
 (3, 2) │ ((dim=2|id=123|"S=1/2,Site,n=3"),)

I think it would be nicer if this convention was reversed.