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/SourceGroupSettingsWithSourceExtensionsJava.h

@@ -1,10 +1,6 @@
 #ifndef SOURCE_GROUP_SETTINGS_WITH_SOURCE_EXTENSIONS_JAVA_H
 #define SOURCE_GROUP_SETTINGS_WITH_SOURCE_EXTENSIONS_JAVA_H
 
-#include "language_packages.h"
-
-#if BUILD_JAVA_LANGUAGE_PACKAGE
-
 #include "SourceGroupSettingsWithSourceExtensions.h"
 
 class SourceGroupSettingsWithSourceExtensionsJava
@@ -17,6 +13,4 @@ private:
 	}
 };
 
-#endif // BUILD_JAVA_LANGUAGE_PACKAGE
-
 #endif // SOURCE_GROUP_SETTINGS_WITH_SOURCE_EXTENSIONS_JAVA_H