cmake: Add install export set

[bwrsandman]

• Set convert_utf as private as it is statically linked so we don't want to export it or its headers.
• Specify libunshield include directory in install interface because it is different than in build-time
  • Removed the redundancy of installing the headers manually
• Add unshield:: cmake namespace export set named unshieldConfig
• Set all targets to the unshieldConfig export set

CMake config sets generate the following files:

• ${install_dir}/lib/cmake/unshieldunshieldConfig.cmake
• ${install_dir}/lib/cmake/unshieldunshieldConfig-${build-config}.cmake

An export set allows CMake users to more easily link with a cmake library which unshield now is. They can now in CMake do the following:

find_package(unshield REQUIRED COMPONENTS unshield libunshield)
target_link_libraries(example PRIVATE unshield::libunshield)
add_custom_target(unshield-version COMMAND unshield::unshield -V)

Using add_custom_target(... unshield::unshield...) can be used as a dependency for another target to generate (extract) files

Also added artifact upload to the cmake tests.

Resulting tree

install
├── bin
│   └── unshield
├── include
│   └── libunshield.h
├── lib
│   ├── cmake
│   │   └── unshield
│   │       ├── unshieldConfig.cmake
│   │       └── unshieldConfig-release.cmake
│   ├── libunshield.so -> libunshield.so.0
│   ├── libunshield.so.0 -> libunshield.so.0.0.0
│   ├── libunshield.so.0.0.0
│   └── pkgconfig
│       └── libunshield.pc
└── share
    └── man
        └── man1
            └── unshield.1

ref: https://cmake.org/cmake/help/latest/guide/importing-exporting/index.html#exporting-targets

[bwrsandman]

Side note, the version is set in https://github.com/twogood/unshield/blob/550ddfe7344c068f9e77a49710bac4f03166b838/lib/CMakeLists.txt#L33

[kratz00]

@bwrsandman Please resolve the conflicts and update your branch, I will have a look then, thanks in advance.

[bwrsandman]

Here are the artifacts that the action generates.

[bwrsandman]

Switched to UPPER

[twogood]

Thank you @bwrsandman and @kratz00 !