feat: add version in url path

cubicweb_api/constants.py

-API_PATH_DEFAULT_PREFIX = "/api/v1"
+API_PATH_DEFAULT_PREFIX = "/api"
 API_ROUTE_NAME_PREFIX = "cube_api_v1_"
 
 DEFAULT_ROUTE_PARAMS = {

cubicweb_api/site_cubicweb.py

@@ -22,7 +22,8 @@
         {
             "type": "string",
             "default": API_PATH_DEFAULT_PREFIX,
-            "help": "prefix used for the url path",
+            "help": "prefix used for the url path. "
+            "The api version number will be added after this prefix (only v1 for now).",
             "group": "api",
             "level": 2,
         },

cubicweb_api/util.py

@@ -41,7 +41,7 @@
     )
     match = re.match("^/[a-zA-Z0-9-_@.&+!*(),/]{1,29}$", path_prefix)
     if match:
-        return path_prefix.rstrip("/")
+        return f"{path_prefix.rstrip('/')}/v1"
     else:
         if len(path_prefix) > 30:
             raise ConfigurationError(