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/vars/main.yml

@@ -0,0 +1,24 @@
+radiusd_example_cert_files:
+- 01.pem
+- 02.pem
+- ca.cnf
+- ca.der
+- ca.key
+- ca.pem
+- client.crt
+- client.csr
+- client.key
+- client.p12
+- client.pem
+- dh
+- index.txt
+- index.txt.attr
+- index.txt.attr.old
+- index.txt.old
+- serial
+- serial.old
+- server.crt
+- server.csr
+- server.p12
+- server.pem
+- user@example.org.pem