[Fixes #90706028] The yAxisMultiTarget had its attribute description set just once during the creationg of the graphView. This didn't take into account that it wouldn't track the attribute description of the y-axis. (The assumption was probably that it didn't change.) Accordingly, in handleAxisModelChange, we now also set the attribute description of the yAxisMultiTarget to match the (possibly new) attribute description of the y-axis.
[Fixes #90706028] The yAxisMultiTarget had its attribute description set just once during the creationg of the graphView. This didn't take into account that it wouldn't track the attribute description of the y-axis. (The assumption was probably that it didn't change.) Accordingly, in handleAxisModelChange, we now also set the attribute description of the yAxisMultiTarget to match the (possibly new) attribute description of the y-axis.

concord-consortium/codap,concord-consortium/codap,concord-consortium/codap,concord-consortium/codap,concord-consortium/codap