Move OidcConfigurationProvider to .oidc package

Issue: gh-5355

config/src/main/java/org/springframework/security/config/oauth2/client/oidc/OidcConfigurationProvider.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.security.config.oauth2.client;
+package org.springframework.security.config.oauth2.client.oidc;
 
 import java.net.URI;
 import java.util.Arrays;

config/src/test/java/org/springframework/security/config/oauth2/client/oidc/OidcConfigurationProviderTests.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.security.config.oauth2.client;
+package org.springframework.security.config.oauth2.client.oidc;
 
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -25,6 +25,7 @@ import org.junit.Before;
 import org.junit.Test;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
+import org.springframework.security.config.oauth2.client.oidc.OidcConfigurationProvider;
 import org.springframework.security.oauth2.client.registration.ClientRegistration;
 import org.springframework.security.oauth2.core.AuthorizationGrantType;
 import org.springframework.security.oauth2.core.ClientAuthenticationMethod;