Discuss options for exposing extensions metadata to API ML

[pablocarle]

We are extending the API ML with an extension that aims to use a custom package name. We will provide code to have this option in the API ML to scan other package names than the ones already defined. An issue that remains to be solved is how to provide this extension base package names to the APIML on startup. One such possibility would be to use the extension manifest: https://docs.zowe.org/stable/extend/packaging-zos-extensions/#zowe-component-manifest