Change OAI license to CSSL v1.0 (and others)

- all RAN code, CI code, configuration files, dockerfiles, in CSSL v1.0
- all deployment code (openshift, charts, ancillary files like shell
  scripts), in MIT
- documentation in CC-BY-4.0
- exceptions might apply and are listed in NOTICE
- there is a new LICENSES folder with all licenses
- CONTRIBUTIONS.md has been updated accordingly

For automated changes based on OAI PL v1.1:

    perl -i~ -0pe 's/\/\*.*Licensed to the OpenAirInterface.*openairinterface.org\n#?/\/*\n * SPDX-License-Identifier: LicenseRef-CSSL-1.0\n/s' **/*.{c,h,cpp}
    perl -i~ -0pe 's/\/\*.*Licensed to the OpenAirInterface.*openairinterface.org\n#?/\/*\n * SPDX-License-Identifier: LicenseRef-CSSL-1.0\n/s' **/*.ts
    perl -i~ -0pe 's/<!--.*Licensed to the OpenAirInterface.*openairinterface.org\n.*-->/<!-- SPDX-License-Identifier: LicenseRef-CSSL-1.0 -->/s' **/*.xml

The rest (cmake, files with missing license, cmake) manually.

tools/packages/packages.cmake

@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: LicenseRef-CSSL-1.0
+
 set(COMPONENTS_LIST "")
 
 set(CPACK_PACKAGE_VERSION ${OAI_VERSION})
@@ -16,7 +18,7 @@ if(PACKAGING_RPM)
   set(CPACK_RPM_COMPONENT_INSTALL ON)
   set(CPACK_RPM_PACKAGE_ARCHITECTURE ${CMAKE_SYSTEM_PROCESSOR})
   set(CPACK_RPM_PACKAGE_URL "https://openairinterface.org")
-  set(CPACK_RPM_PACKAGE_LICENSE "OAI Public License v1.1")
+  set(CPACK_RPM_PACKAGE_LICENSE "Collaborative Standards Software License v1.0")
   set(CPACK_RPM_PACKAGE_GROUP "Development/Tools")
   set(SYSTEMD_UNIT_DIR "/usr/lib/systemd/system")
   set(CPACK_RPM_DEBUGINFO_PACKAGE ON)