Move "clapper_src" dir to "src"

The "clapper_src" directory name was unusual. This was done to make it work as a widget for other apps. Now that this functionality got removed it can be named simply "src" as recommended by guidelines.

src/mainRemote.js

@@ -0,0 +1,15 @@
+imports.gi.versions.Gdk = '4.0';
+imports.gi.versions.Gtk = '4.0';
+
+const { AppRemote } = imports.src.appRemote;
+const Misc = imports.src.misc;
+
+const ID_POSTFIX = 'Remote';
+
+Misc.clapperPath = `${pkg.datadir}/${Misc.appId}`;
+Misc.appId += '.' + ID_POSTFIX;
+
+function main()
+{
+    new AppRemote().run();
+}