* Add SPDX-License-Identifier in src/common
* Add SPDX-License-Identifier in FrodoKEM
* Add SPDX-License-Identifier in SIKE
* Add SPDX-License-Identifier in BIKE
* Add SPDX-License-Identifier in OQS headers
* Add SPDX-License-Identifier in files generated during copy-from-pqclean
* Add SPDX-License-Identifier in Picnic
* Add SPDX-License-Identifier in qTesla
* Add SPDX-License-Identifier in CMake files
* Update license info in README
* Add SPDX-License-Identifier in scripts
* Add SPDX-License-Info to CMakeLists
* Add SPDX-License-Info in tests
* Add SPDX-License-Info to various files
* Prettyprint
* Add test for SPDX-License-Identifier headers
* Updated license identifiers for CPU extension detection code.
* Use conjunction for SPDX in file with two licenses
Co-authored-by: xvzcf <xvzcf@users.noreply.github.com>
