[Feat]: ability to group by any host label when using overview dashboard

[andrewm4894]

Problem

stemming from a user question.

It would be good to be able to group by host label when using netdata charts too.

For example say some of my nodes are in different regions - i might want to label each node by region and then have ability to group by region too in netdata charts.

The example here is obvious: https://learn.netdata.cloud/docs/configuring/organize-systems-metrics-and-alerts#custom-labels

Lets say i want to be able to group by location to see my metrics aggregated by nodes matching each location custom label.

Description

ideally custom node labels would just be available in here:

Importance

really want

Value proposition

1. much more flexibility and powerful aggregation capabilities

Proposed implementation

i think it means host labels would in some way (by agent or cloud?) need to be propagated to the chart/context level so that they are available on all charts.