Only show estimation on the last datapoint in download charts #1318
Description
Currently for incomplete periods, both the estimation and the last datapoint are visible.
Only show the estimation in this case:
- swap the last datapoint with the estimation in the dataset passed to VueUiXy
- remove the nice scale adaptations that will not be necessary anymore as the estimation will be part of the chart's native data
- remove the opacifying line overlay currently positioned on the last datapoint
- add an overlay to cover the last segment, under the dashed segment already implemented