Add meta data for nep-explorer

[jwildfire]

Team to update meta_labs and create a new meta_nepExplorer data object that defines the required metadata for the charts.

Once the new meta_vitals domain is available, we'll need to refactor to combine vitals and labs in an init function over in the nep-explorer repo.

cc: @pburnsdata @elimillera @lgakava @jwoolfolk

[pburnsdata]

so we'd potentially touch meta_labs, meta_dm, meta_vitals, and create a meta_nepExplorer for our measure values