refactor: switch to rum-distiller for oversight

[karlpauls]

With the new rum-distiller (https://github.com/adobe/rum-distiller) project we are trying to factor out the cruncher and the definitions of the series and facets into a common project.

Test: https://distiller-oversight--helix-website--adobe.aem.live/tools/oversight/explorer.html?domain=blog.adobe.com&domainkey=incognito