Runtime footprint needs to be reduced

[hsolbrig]

The pypi image currently requires the whole of biolinkml (soon to be linkml). While the whole package is needed to generate the output, the runtime portion should be cut down to the minimal libraries needed to support YAMLRoot and its relatives. This update should be done once we get linkml fully split into three components (model, runtime and development packages)

[hsolbrig]

Done