scatter-vis: Show labels for selected items in scatter plot

[dvchristianbors]

Short description

To facilitate using the scatter vis for presentation purposed, we shoult show the labels for items the user has selected

In order to prevent overplotting, we should introduce a maximum number of labels shown (e.g., 20, but this number likely needs to be determined during development).

User stories

• As a user, I want to be able to see all labels for items that I are currently selected in the scatter vis, so that I can create a screenshot of the plot and use it to present value differences between my selections.
  

Please make sure this feature request hasn't been already submitted by someone by looking through other open/closed issues 😃

[dv-raghad-jamalaldeen]

To address this we will use labeling as in the picture and provide three options (show all labels, show labels for selected items, and hide labels)