BUG+TST: setdiag implementation for dia_matrix (Close #2931) + test_setdiag (was untested)

Revealed similar lack of setdiag imlementation for COO and BSR matrices (TODO)
TST: mark test_setdiag for BSR and COO as a known failure
enable setdiag for non pre-existing offsets
Fixing off-diag impl, adding test case.
Workaround format hack.
BUG: sparse: preserve offsets dtype in setdiag
Merge pull request #2932 from pr-2932

BUG: sparse: setdiag implementation for dia_matrix