Allow Marker to taken into account when auto calculating max value

[JoepVerkoelen]

Preface: This request is similar to an older ticket (#1385). It was closed without implementing and the original poster raised a concern with the proposed solution which was left unanswered. I find myself with the same request and the same concern with the then proposed solution, hence this new issue (as the old one was 4 years old and it felt wrong to resurrect it).

Is your feature request related to a problem? Please describe.
When a marker is added to a (responsive) bar chart, and the value is higher than any of the bars, it is not visible when using 'auto' to calculate the maximum.
For instance: When I have a budget line at 400, but the stacked expenses bars are 300 at most, there is no visible budget line. This defeats the purpose of
a) graphs to create quick overview of general data and relations (by immediately showing that these expenses are within budget), and
b) auto calculating the max vaue because that already handles all the other dynamic options like stacking.

In short: I would like a way to ensure that a certain value (whether they be min or max, although my immediate usecase is for max) is visible on the axis.

Describe the solution you'd like
It would be great if there was either:

1. A Marker property that allows a marker value to be taken into account with the 'auto' calculations of min and max
2. A Barchart property that allows me to define a minimum value that the max should have (and for symmetry purposes a maximum value for the min property as well)
3. Expose the calculation function for 'auto' to run the calculation without duplication (least favourite option)
4. Add post calculation hooks for custom calculations (calculated max) -> new max

Describe alternatives you've considered
I could calculate the max myself, but since we use the dynamic presentations of these charts, that means that I have to rebuild the logic that should already be present in the package.

Additional context
The project uses different graphs and different data sets which change over time. It is impossible to predict a fixed 'max' value without explicitly duplicating the calculation.