feat: manage timezone per region

- add timezone module
- set per-region timezone setting
- setup hiera_classes, set to deep merge, and set to include all in base profile

site/profiles/manifests/base.pp

@@ -60,4 +60,7 @@ class profiles::base (
   if $::facts['is_virtual'] and $::facts['dmi']['manufacturer'] == 'QEMU' {
     include profiles::qemu::agent
   }
+
+  # include classes from hiera
+  lookup('hiera_classes', Array[String], 'unique').include
 }