Persist EuroOffice DATA_DIR as a volume

The euro-office image intends /var/www/euro-office/Data to be persistent
(its entrypoint stores the generated JWT secret and WOPI keys there and
prints 'Mount ${DATA_DIR} as a volume to persist it across restarts');
the generate-allfonts script also scans Data/custom-fonts for user-provided
fonts on every container start.

Without a volume, custom fonts and the generated secrets are lost whenever
the container is recreated on update. Mount a dedicated volume and include
it in backup_volumes (it is small: keys + fonts), unlike the reinstallable
documentserver volume.

The schema's path pattern is extended to allow capital letters because the
Data directory inside the image is capitalized.

Resolves the persistence gap discussed in #8493.

Signed-off-by: deschoene <74868758+deschoene@users.noreply.github.com>

php/containers-schema.json

@@ -216,7 +216,7 @@
 							"properties": {
 								"destination": {
 									"type": "string",
-									"pattern": "^((/[a-z_/.-]+)|(%[A-Z_]+%))$"
+									"pattern": "^((/[a-zA-Z_/.-]+)|(%[A-Z_]+%))$"
 								},
 								"source": {
 									"type": "string",

php/containers.json

@@ -795,8 +795,16 @@
           "source": "nextcloud_aio_eurooffice",
           "destination": "/var/lib/euro-office",
           "writeable": true
+        },
+        {
+          "source": "nextcloud_aio_eurooffice_data",
+          "destination": "/var/www/euro-office/Data",
+          "writeable": true
         }
       ],
+      "backup_volumes": [
+        "nextcloud_aio_eurooffice_data"
+      ],
       "secrets": [
         "EUROOFFICE_SECRET"
       ],