build: allow to disable language support in cmake

* in addition: add unloadable sourcegroup to visualize, load and save information when loading a project that contains source groups that are not supported by the build

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

@@ -1,5 +1,7 @@
 #include "SourceGroupSettingsWithJavaGradle.h"
 
+#if BUILD_JAVA_LANGUAGE_PACKAGE
+
 #include "ConfigManager.h"
 #include "ProjectSettings.h"
 #include "utilityFile.h"
@@ -56,3 +58,5 @@ void SourceGroupSettingsWithJavaGradle::save(ConfigManager* config, const std::s
 	config->setValue(key + "/gradle/project_file_path", getGradleProjectFilePath().wstr());
 	config->setValue(key + "/gradle/should_index_tests", getShouldIndexGradleTests());
 }
+
+#endif // BUILD_JAVA_LANGUAGE_PACKAGE