roles/freeradius: Role to deploy RADIUS with EAP-TLS

The *freeradius* role is used to install and configure FreeRADIUS. The
configuration system for it is extremely complicated, with dozens of
files in several directories. The default configuration has a plethora
of options enabled that are not needed in most cases, so they are
disabled here. Since the initial (and perhaps only) use case I have for
RADIUS is WiFi authentication via certificates, only the EAP-TLS
mechanism is enabled currently.

roles/freeradius/defaults/main.yml

@@ -0,0 +1,35 @@
+radiusd_default_eap_type: tls
+radiusd_dhparm_size: 2048
+radius_client_secrets: {}
+radiusd_disable_modules:
+- attr_filter
+- cache_eap
+- chap
+- date
+- detail
+- detail.log
+- dhcp
+- digest
+- dynamic_clients
+- echo
+- exec
+- expiration
+- expr
+- files
+- linelog
+- logintime
+- mschap
+- ntlm_auth
+- pap
+- passwd
+- preprocess
+- radutmp
+- realm
+- replicate
+- soh
+- sradutmp
+- unix
+- unpack
+- utf8
+radiusd_disable_sites:
+- inner-tunnel