Add an hourly heatmap chart type

[tomlut]

Why is this needed:

According to this blog post the 3rd party carpet plot and its replacement, hourly heat map, have been extremely popular plug-ins. I personally use it extensively and find it invaluable for easy and quick data visualisation checks.

Neither plug-ins are being actively supported and neither are compatible with the latest releases of Grafana. I have not updated for a while and am still running Grafana 10.1.2 because of this.

The Grafana Labs Heatmap chart does not come close to the functionality these 3rd party plug-ins offered. Compare the information available:

Grafana Labs Heatmap

Carpet-plot:

What would you like to be added:

A chart that has time on the Y-axis, binned by hour, date on the X-axis, and measured value represented by the colour of the cell. e.g.

Who is this feature for?

The large number of people who used to use the 3rd party plug-ins.