stricter buffer sizes in SparseMatrixCSC (#40523)
Make length(A.nzval)==nnz(A) and add strict buffer checking (#30662)
* Add sizehint!(::SparseMatrixCSC, args...),
* Fix illegal SparseMatrixCSC construction in cholmod and linalg.
* Remove tests targetting now illegal buffers
* Fix invalid buffer creation in kron and more
* use widelength in sizehint! to cope with large matrices in 32 bit systems
