from: toolkit-maven-plugin
to: codegen
evidence:
 - file: "toolkit-maven-plugin/src/main/java/org/apache/servicecomb/toolkit/plugin/GenerateUtil.java"
   contains "import org.apache.servicecomb.toolkit.codegen.GeneratorExternalConfigConstant;"

from: toolkit-maven-plugin
to: codegen
evidence:
 - file: "toolkit-maven-plugin/src/main/java/org/apache/servicecomb/toolkit/plugin/GenerateMojo.java"
   contains "import org.apache.servicecomb.toolkit.codegen.GeneratorExternalConfigConstant;"