feat: add a finally callback to NetworkRequests (#2350)

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>

src/common/NetworkCommon.hpp

@@ -12,6 +12,7 @@ class NetworkResult;
 using NetworkSuccessCallback = std::function<Outcome(NetworkResult)>;
 using NetworkErrorCallback = std::function<void(NetworkResult)>;
 using NetworkReplyCreatedCallback = std::function<void(QNetworkReply *)>;
+using NetworkFinallyCallback = std::function<void()>;
 
 enum class NetworkRequestType {
     Get,