set PluginClassLoader for plugin config

[lilai23]

What happened?

When using snakeyaml to transform dynamic config content to an object of config class，snakeyaml tries to search the BeanInfo of this class. It will cause stack overflow for PluginClassloader and ServiceClassloader depend on each other to find BeanInfo class. In fact，BeanInfo is not necessary.

How can we reproduce it (as minimally and precisely as possible)?

You can reproduce it when resolving dynamic config content via snakeyaml in case of the dynamic config class is defined and used only in service module

Anything else we need to know?

No response

Sermant version

1.3.1