Issue Description

Type: feature request

1. Starting from agollo v4.0.10, the agollo.Client has transitioned from a struct to an interface type, and agollo.StartWithConfig now returns this interface. Consequently, the current apolloDatasource is no longer compatible with newer versions of agollo.
2. Currently, using the agollo.Client.GetValue method directly retrieves configuration information by querying the default application namespace. We hope to enable the option to retrieve Sentinel rules from a specified namespace.

Describe what feature you want

1. Create a new specialized ApolloClient interface to replace *agollo.Client, enabling apolloDataSource to be compatible with all current versions of agollo.
2. add WithNamespace option

Additional context