Add feature flag for reply in thread

Currently the ability to reply in threads was added but not the ability to actually view threads so this doesn't currently make much sense to just have enabled int he main build.

Note: I want to cherrypick this so it's just the flag. I'll add a feature flag page to dev tools for master soon.


(cherry picked from commit 864f9b8f74)

src/neochatconfig.kcfg

@@ -156,5 +156,11 @@
       <default></default>
     </entry>
   </group>
+  <group name="FeatureFlags">
+    <entry name="Threads" type="bool">
+      <label>Enable threads</label>
+      <default>false</default>
+    </entry>
+  </group>
 </kcfg>