The Nuxeo platform Python scripts should be available in a downloadable artifact

The release & release_mp script (and the associated lib) are only available by cloning the platform sources, which can be quite heavy now that we use Jenkins pipelines.
Those scripts should be available in an independent artifact still built from the platform sources but uploaded on a distribution solution like Nexus.
Suggested artifact:

  <groupId>org.nuxeo</groupId>
  <artifactId>nuxeo-ecm</artifactId>
  <version>9.1</version>
  <classifier>tools</classifier>
  <type>zip</type>