Add Nextcloud deployment and configuration

- Introduced Nextcloud module with Kubernetes resources including deployment, service, ingress, and cron job.
- Configured Apache settings for Nextcloud with SSL support and compression.
- Created secrets for mail and admin credentials.
- Added necessary environment variables for Nextcloud configuration.
- Removed unused Scaleway access and secret keys from secrets and variables.
- Updated CoreDNS module to support custom host overrides.
- Implemented backup bucket policies and lifecycle rules for Scaleway object storage.
- Enhanced IAM policies and applications for backup and email services.
- Added outputs for backup bucket and API keys.

terraform/modules/apps/nextcloud/resources/nextcloud-server-snippet.conf

@@ -0,0 +1,32 @@
+server_tokens off;
+proxy_hide_header X-Powered-By;
+
+location = /.well-known/webfinger {
+  return 301 $scheme://$host/index.php/.well-known/webfinger;
+}
+
+location = /.well-known/nodeinfo {
+  return 301 $scheme://$host/index.php/.well-known/nodeinfo;
+}
+
+location = /.well-known/carddav {
+  return 301 $scheme://$host/remote.php/dav;
+}
+
+location = /.well-known/caldav {
+  return 301 $scheme://$host/remote.php/dav;
+}
+
+location = /robots.txt {
+  allow all;
+  log_not_found off;
+  access_log off;
+}
+
+location ~ ^/(?:build|tests|config|lib|3rdparty|templates|data)/ {
+  deny all;
+}
+
+location ~ ^/(?:autotest|occ|issue|indie|db_|console) {
+  deny all;
+}