Scrub cursors are missing from chart

[djbarnwal]

Hover over a scrub or scrub edges should change the cursor as mentioned here -https://www.notion.so/rilldata/Enable-scrub-to-filter-on-measure-line-charts-5a662647d43e4e23937a709145bbdd9c

This was added with the initial scrub implementation but seems like there has been a regression.