add: config to emit warning for legacy target names

Adds the `url_use_legacy_target_names` config.

Enabled (default):
* It allows using the resource name in filters,
  orders or limits when it has an alias, e.g.
  `table?select=alias:target(*)&target.id=eq.1`
* Logs a WARNING with a hint to use the alias
* Returns a Warning header in the response

Disabled:
* It returns an error, only the alias is allowed
* No warnings returned

This feature is deprecated

test/io/configs/no-defaults.config

@@ -38,6 +38,7 @@ server-trace-header = "X-Request-Id"
 server-timing-enabled = true
 server-unix-socket = "/tmp/pgrst_io_test.sock"
 server-unix-socket-mode = "777"
+url-use-legacy-target-names = false
 admin-server-port = 3001
 admin-server-host = "127.0.0.1"
 admin-server-unix-socket = "/tmp/admin_io_test.sock"