build: Only add language package specific source and header files to build when enabled

* removed preprocessor guards in language specific files to avoid "file has no symbols" warning
* separated files into multiple lists in lib and lib_gui CMakeLists.txt for each language package

src/lib/settings/source_group/component/java/SourceGroupSettingsWithJavaMaven.cpp

@@ -1,7 +1,5 @@
 #include "SourceGroupSettingsWithJavaMaven.h"
 
-#if BUILD_JAVA_LANGUAGE_PACKAGE
-
 #include "ConfigManager.h"
 #include "ProjectSettings.h"
 #include "utilityFile.h"
@@ -58,5 +56,3 @@ void SourceGroupSettingsWithJavaMaven::save(ConfigManager* config, const std::st
 	config->setValue(key + "/maven/project_file_path", getMavenProjectFilePath().wstr());
 	config->setValue(key + "/maven/should_index_tests", getShouldIndexMavenTests());
 }
-
-#endif // BUILD_JAVA_LANGUAGE_PACKAGE