Move remaining code to app module

There's still some stuff that could potentially go elsewhere but I think it's enough for now.

src/libneochat/jobs/neochatgetcommonroomsjob.h

@@ -0,0 +1,13 @@
+// SPDX-FileCopyrightText: 2024 Joshua Goins <josh@redstrate.com>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <Quotient/jobs/basejob.h>
+
+// TODO: Upstream to libQuotient
+class NeochatGetCommonRoomsJob : public Quotient::BaseJob
+{
+public:
+    explicit NeochatGetCommonRoomsJob(const QString &userId);
+};