Replace Quotient::Connection with NeoChatConnection where possible

(cherry picked from commit 1e644587b3)

src/spacehierarchycache.h

@@ -116,5 +116,5 @@ private:
     QHash<QString, Quotient::Omittable<QString>> m_nextBatchTokens;
     void populateSpaceHierarchy(const QString &spaceId);
     void addBatch(const QString &spaceId, Quotient::GetSpaceHierarchyJob *job);
-    NeoChatConnection *m_connection;
+    QPointer<NeoChatConnection> m_connection;
 };