Support for "Metric" Entity Type

Datahub does not have an entity type for “metrics“. I would be so happy if we had one!

Metrics are entities calculated and served via different ways such as REST or via data stores. You can think these as the standard application metrics(such as the ones Datahub exposes via jmx), but calculated from the data itself. Metrics has a name, definition(as a document), a way of calculation(which does not in the scope of the question) and dimensions. Dimension is a term agian used in the application metrics.

An example metric might be "number of sessions". Dimensions of can be time window, user type etc.

The change seems straightforward, explained in https://datahubproject.io/docs/metadata-modeling/extending-the-metadata-model. The challenge might be deciding the fields of the new type.