Fix variable substitution in users_database.yml

- Update localize_users_database_file to properly resolve nested variables in AUTHELIA_ADMIN_EMAIL
- Fix template to use correct AUTHELIA_* variables instead of DEFAULT_* variables
- Update deploy-core.sh to only process files containing variables and fix .env path
- Fix file permissions for authelia config files

docker-compose/core/authelia/secrets/users_database.yml

@@ -0,0 +1,19 @@
+# yamllint disable rule:line-length
+---
+###############################################################
+#                         Users Database                      #
+###############################################################
+
+# This file can be used if you do not have an LDAP set up.
+
+users:
+  authelia:
+    disabled: false
+    displayname: "Test User"
+    password: "$argon2id$v=19$m=32768,t=1,p=8$eUhVT1dQa082YVk2VUhDMQ$E8QI4jHbUBt3EdsU1NFDu4Bq5jObKNx7nBKSn1EYQxk"  # Password is 'authelia'
+    email: authelia@authelia.com
+    groups:
+      - admins
+      - dev
+...
+# yamllint enable rule:line-length