Rest Catalog Refresh Access Token with stored CLIENT_ID and CLIENT_SECRET

[sungwy]

Feature Request / Improvement

If the token fetched by PyIceberg client expires, The REST Catalog server will issue a 419 status response, which will result in a AuthorizationExpiredError.

Currently, PyIceberg only fetches the access_token using the stored CLIENT_ID and CLIENT_SECRET upon creating a new request session, which is initialized only when a new RestCatalog is initialized.

Instead of throwing an exception, we should refresh the access token by invoking self._fetch_access_token again using the stored credentials. This feature enhancement will allow a PyIceberg client to support tasks that take longer than the life time of an access token, which can be as short as a minute (depends on the security restrictions of the auth provider).