[WIP] launcherlib: Fix "different visibility" warning including GenerateExportHeader

[jcfr]

This commit is an attempt to "different visibility" warning [1]. By including "GenerateExportHeader" header, it automatically run the try_compile checking if compiler support "visibility" flags and set option "USE_COMPILER_HIDDEN_VISIBILITY" to ON if it makes sense.

[...]
-- Checking to see if CXX compiler accepts flag -fvisibility=hidden
-- Checking to see if CXX compiler accepts flag -fvisibility=hidden - yes
-- Performing Test COMPILER_HAS_HIDDEN_VISIBILITY
-- Performing Test COMPILER_HAS_HIDDEN_VISIBILITY - Success
-- Performing Test COMPILER_HAS_HIDDEN_INLINE_VISIBILITY
-- Performing Test COMPILER_HAS_HIDDEN_INLINE_VISIBILITY - Success
-- Performing Test COMPILER_HAS_DEPRECATED_ATTR
-- Performing Test COMPILER_HAS_DEPRECATED_ATTR - Success
[...]

[jcfr]

Revisit this and remove CMake function ctkFunctionGetCompilerVisibilityFlags