fix(pyramid): Prefix json renderer name to avoid conflicts

If a "json" renderer is already defined in the project, a conflict appeared.
Now the renderer is prefixed, there is not more conflict.

cubicweb_api/__init__.py

@@ -41,5 +41,5 @@
     json_renderer.add_adapter(date, datetime_adapter)
     json_renderer.add_adapter(time, datetime_adapter)
 
-    config.add_renderer("json", json_renderer)
+    config.add_renderer("cubicweb_api_json", json_renderer)
     config.include(".routes")

cubicweb_api/constants.py

@@ -22,7 +22,7 @@
 # Default parameters to use for API routes.
 DEFAULT_ROUTE_PARAMS = {
     "request_method": "POST",
-    "renderer": "json",
+    "renderer": "cubicweb_api_json",
     "require_csrf": False,
     "openapi": True,
 }