Harmonize license/copyright with Rizin with SPDX

[XVilka]

Use the same scheme as Rizin does. For example, header could look like this:

//  SPDX-FileCopyrightText: 2019 Jane Doe <[email protected]>
//  SPDX-License-Identifier: GPL-3.0-or-later

More at https://reuse.software/faq/#quick-summary

See also rizinorg/rizin#683

[i] ℤ reuse lint                                                                                                                                                                                                                  12:48:35 
# MISSING LICENSES

'LGPL-3.0-or-later' found in:
* cutter-plugin/RzGhidraDecompiler.cpp
* cutter-plugin/RzGhidraDecompiler.h
* cutter-plugin/RzGhidraPlugin.cpp
* cutter-plugin/RzGhidraPlugin.h
* src/ArchMap.cpp
* src/ArchMap.h
* src/CodeXMLParse.h
* src/RizinArchitecture.cpp
* src/RizinArchitecture.h
* src/RizinCommentDatabase.cpp
* src/RizinCommentDatabase.h
* src/RizinLoadImage.cpp
* src/RizinLoadImage.h
* src/RizinPrintC.cpp
* src/RizinPrintC.h
* src/RizinScope.cpp
* src/RizinScope.h
* src/RizinTypeFactory.cpp
* src/RizinTypeFactory.h
* src/RizinUtils.h
* src/RzCoreMutex.h
* src/SleighAnalysisValue.cpp
* src/SleighAnalysisValue.h
* src/SleighAsm.cpp
* src/SleighAsm.h
* src/SleighInstruction.cpp
* src/SleighInstruction.h
* src/analysis_ghidra.cpp
* src/asm_ghidra.cpp
* src/core_ghidra.cpp


# MISSING COPYRIGHT AND LICENSING INFORMATION

The following files have no copyright and licensing information:
* .builds/freebsd.yml
* .builds/openbsd.yml
* .github/vsdevenv.ps1
* .github/workflows/ci.yml
* .github/workflows/codeql-analysis.yml
* .github/workflows/coverity-scan.yml
* .github/workflows/dist.yml
* .gitignore
* .gitmodules
* .travis.yml
* CMakeLists.txt
* README.md
* assets/logo.svg
* cmake/FindCutter.cmake
* cmake/FindRizin.cmake
* cutter-plugin/CMakeLists.txt
* ghidra/CMakeLists.txt
* rz_ghidra.pc.in
* scripts/Dockerfile.arch
* scripts/Dockerfile.buster
* scripts/ci-script
* src/CodeXMLParse.cpp
* src/RzCoreMutex.cpp
* src/rz_ghidra.h
* test/.gitignore
* test/Makefile
* test/bins/Makefile
* test/bins/dectest.c
* test/bins/dectest32
* test/bins/dectest64
* test/bins/hello-arm
* test/bins/jni-simplified.h
* test/bins/rec
* test/bins/rec.c
* test/bins/strings
* test/bins/strings.c
* test/bins/types.h
* test/bins/types_rec.h
* test/db/extras/analysis_ghidra
* test/db/extras/asm_ghidra
* test/db/extras/ghidra
* third-party/CMakeLists.txt

The following files have no copyright information:
* cutter-plugin/RzGhidraDecompiler.cpp
* cutter-plugin/RzGhidraDecompiler.h
* cutter-plugin/RzGhidraPlugin.cpp
* cutter-plugin/RzGhidraPlugin.h
* src/ArchMap.cpp
* src/ArchMap.h
* src/CodeXMLParse.h
* src/RizinArchitecture.cpp
* src/RizinArchitecture.h
* src/RizinCommentDatabase.cpp
* src/RizinCommentDatabase.h
* src/RizinLoadImage.cpp
* src/RizinLoadImage.h
* src/RizinPrintC.cpp
* src/RizinPrintC.h
* src/RizinScope.cpp
* src/RizinScope.h
* src/RizinTypeFactory.cpp
* src/RizinTypeFactory.h
* src/RizinUtils.h
* src/RzCoreMutex.h
* src/SleighAnalysisValue.cpp
* src/SleighAnalysisValue.h
* src/SleighAsm.cpp
* src/SleighAsm.h
* src/SleighInstruction.cpp
* src/SleighInstruction.h
* src/analysis_ghidra.cpp
* src/asm_ghidra.cpp
* src/core_ghidra.cpp


# SUMMARY

* Bad licenses:
* Deprecated licenses:
* Licenses without file extension:
* Missing licenses: LGPL-3.0-or-later
* Unused licenses:
* Used licenses:
* Read errors: 0
* Files with copyright information: 0 / 72
* Files with license information: 30 / 72

Unfortunately, your project is not compliant with version 3.0 of the REUSE Specification :-(

[XVilka]

Fixed in 0c84e0d