Dashboard Graph: Labels etc based on query results

__Proposal:__
Current: The Y-axis suffix is a fixed text that you can enter in the graph options.
Desired: In my case this suffix is part of the dataset. (i.e. liters and liters per hour)
.................I think it would be usefull if this suffix (and other graph properties) could be taken from the dataset.

__Current behavior:__
The Y-axis suffix is a fixed text that you can enter in the graph options.

__Desired behavior:__
Optionally the Y-axis suffix is a text that depends on the data in the query.

__Alternatives considered:__
None

__Use case:__
Almost every datapoint that you measure has a dimension (like km/hr or liters or meters etc). I think it makes sense to include this dimension in the data (as a key in my case). If it's in the data then it makes sense to be able to show it in the graph so the viewer doesn't have to guess. If you change the data then the dimension automatically changes with it. No need to manually enter it.

Start with the dashboard graph options and query-result handling described in the issue, then determine how dataset dimensions could be exposed to graph properties. Done means the Y-axis suffix can optionally follow the query data and changes automatically when the dataset changes.

Written by the indexing model from the issue text.