Update build process to copy output explorer.js to explorer-n.n.n.js

[darrelmiller]

Add a step to the azure-pipelines.yml to create a copy of our explorer.js and explorer.js.map files with a version suffix. We can either get the version from the package.json or from the build environment. We should try and identify what the best practices are.

[darrelmiller]

As we don't need this anymore. Can we remove this process just to clean up.