[Lens] CSV Download contains original instead of overridden axis titles

[veitvw]

Describe the bug:
When choosing a custom axis title for an axis in a graph, e.g. choosing the title "date" in the horizontal axis of a bar vertical stacked to get rid of the title "[my data] per time interval", the downloaded csv of the graph doesn't containt the custom title "date" for that column but the original title "[my data] per time interval"

Steps to reproduce:

1. create bar vertical stacked
2. choose Date histogram as Horizontal axis
3. Overwrite Bottom axis title
4. Download csv

Expected behavior:

The custom title should be shown in the csv. I give that axis of my visualisation a custom name to represent what the data shows, i want that name to be in the csv as well.

[veitvw]

duplicate:

#98054