Adding SSL support to eole-redis.

Ubuntu don't build redis with SSL support so we
use Stunnel to fill the gap.

Here we add Stunnel full EOLE integration and Redis specifics.

Maybe later we will want to have a specific package for eole-stunnel.

ref #30338

tmpl/90-stunnel_dynamic_rules

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+%for %%tunnel in %%stunnel_name
+   %for %%int_idx in %%range(0, %%int(%%nombre_interfaces))
+/sbin/iptables -A eth%%{int_idx}-root -s 0.0.0.0/0.0.0.0  -p tcp -m tcp --dport %%tunnel.stunnel_accept_port --tcp-flags FIN,SYN,RST,ACK SYN -j ACCEPT
+   %end for
+%end for