cleanup site replication error handling (#15113)

site replication errors were printed at
various random locations, repeatedly - this
PR attempts to remove double logging and
capture all of them at a common place.

This PR also enhances the code to show
partial success and errors as well.

cmd/admin-handler-utils.go

@@ -96,6 +96,12 @@ func toAdminAPIErr(ctx context.Context, err error) APIError {
 		}
 	default:
 		switch {
+		case errors.Is(err, errTooManyPolicies):
+			apiErr = APIError{
+				Code:           "XMinioAdminInvalidRequest",
+				Description:    err.Error(),
+				HTTPStatusCode: http.StatusBadRequest,
+			}
 		case errors.Is(err, errDecommissionAlreadyRunning):
 			apiErr = APIError{
 				Code:           "XMinioDecommissionNotAllowed",