ENH: add methods to jump to slice location

Provide a method to jump to the first point in the nth markup in a list.
Uses the new method to jump the slices to a xyz location.
ENH: on click in the name column, jump slices to that point location

Use the logic methods to jump the slices after extracting
the location from the item clicked on.
For now, clicking in the name column triggers the jump slices.
Set selection mode to row and allow multi select for future
mass operations.

TODO: make a new column to click in for jump or implement righ click
on the row.
STYLE: comment out debugging comments
ENH: don't respond to the seed widget unless it's moving

BUG: not using the check in 2d as it disables the widgets somehow