LineTooltipItem

** Don't make a duplicate issue.
You can search in issues to make sure there isn't any already opened issue with your concern.

**Is your feature request relasted to a problem? Please describe.**
LineTooltipItem has no gestures

**Describe the solution you'd like**
Add a click event

**Describe alternatives you've considered**
Offset is used for positioning in touchCallback, but the coordinates are inconsistent with those given by chart

**Additional context**
Add any other context or screenshots about the feature request here.

Start by tracing LineTooltipItem and the touchCallback entry point in the chart interaction code; the issue does not name specific files or tests. Compare the coordinates supplied by touchCallback with those supplied by the chart, then determine how a click event should be exposed. Done means LineTooltipItem supports the requested click interaction with consistent positioning.

Written by the indexing model from the issue text.