src: clazy compiler warnings

get rid of most clazy warnings (https://github.com/KDE/clazy)
* range loop use refs
* qcolor ctor with ints
* missing Q_OBJECT macro
* use .constfirst instead of .first

enabled ccache for unix systems for fasterr recompiling
* if ccache is in path we use it now

src/lib/data/storage/StorageProvider.cpp

@@ -60,7 +60,7 @@ void StorageProvider::logCurrentState() const
 	std::string logString = "Storages waiting for injection:";
 	{
 		std::lock_guard<std::mutex> lock(m_storagesMutex);
-		for (std::shared_ptr<IntermediateStorage> storage: m_storages)
+		for (const std::shared_ptr<IntermediateStorage>& storage: m_storages)
 		{
 			logString += " " + std::to_string(storage->getSourceLocationCount()) + ";";
 		}