Distance & Planning - add cruise flight level

[Loma]

As a Windy user, I would like to have an option to choose a cruise flight level, so I can better see the weather conditions on the vertical chart.

Given I view the Distance & Planning
When I enter a cruise flight level
Then a line at that flight level on the vertical chart appears

Side note: that vertical chart could be even further enhanced by adding toggleable CAT, icing, and clouds overlays. Also, what would be super useful is if we could have that vertical chart taller (open in a new tab or a modal?).