SPDX: Improve license parsing to check license identifier and avoid duplicate
Improve license parsing to check license identifier and avoid duplicate
Currently, vtkCommonCore.spdx license identifier looks like that:
PackageLicenseConcluded: BSD-3-Clause AND BSD-3-Clause AND Apache-2.0 AND BSD-3-Clause AND MIT AND BSD-3-Clause AND BSD-2-Clause AND LicenseRef-BSD-3-Clause-Sandia-USGov
It would be better to actually parse the content of the license identifiers, including the AND
and other logical operators and make sure license identifiers are actually valid.