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.cpp

@@ -0,0 +1,11 @@
+// SPDX-FileCopyrightText: 2024 Joshua Goins <josh@redstrate.com>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "neochatgetcommonroomsjob.h"
+
+using namespace Quotient;
+
+NeochatGetCommonRoomsJob::NeochatGetCommonRoomsJob(const QString &userId)
+    : BaseJob(HttpVerb::Get, u"GetCommonRoomsJob"_s, "/_matrix/client/unstable/uk.half-shot.msc2666/user/mutual_rooms", QUrlQuery({{u"user_id"_s, userId}}))
+{
+}