Dots in displaying views of sparse/structured arrays (#51679)
With this, views of sparse/structured arrays are printed with dots as
well:
```julia
julia> D = Diagonal(1:4)
4×4 Diagonal{Int64, UnitRange{Int64}}:
1 ⋅ ⋅ ⋅
⋅ 2 ⋅ ⋅
⋅ ⋅ 3 ⋅
⋅ ⋅ ⋅ 4
julia> view(D, 1:3, 1:3)
3×3 view(::Diagonal{Int64, UnitRange{Int64}}, 1:3, 1:3) with eltype Int64:
1 ⋅ ⋅
⋅ 2 ⋅
⋅ ⋅ 3
julia> S = sparse([1,2,2,2,3], [1,1,2,2,4], [5, -19, 73, 12, -7])
3×4 SparseMatrixCSC{Int64, Int64} with 4 stored entries:
5 ⋅ ⋅ ⋅
-19 85 ⋅ ⋅
⋅ ⋅ ⋅ -7
julia> view(S, 1:3, 1:3)
3×3 view(::SparseMatrixCSC{Int64, Int64}, 1:3, 1:3) with eltype Int64:
5 ⋅ ⋅
-19 85 ⋅
⋅ ⋅ ⋅
```
