Remove all artifactory dependencies in `cn-quickstart`

[dasormeter]

Motivation

Remove all dependencies on artifacts from artifactory that require a token and user registration to smooth any friction points for getting up and running with cn-quickstart

Changes Required

These include

• Pull daml sdk from github (publicly accessible) rather than artifactory -- handling of slightly different versioning and artifact naming required
• Pull grafana example dashboards from a known public location (also scribe should be updated to publish these grafana dashboard to a publicly accessible location rather than artifactory)