[ENH] owkaplanmeier: change the symbol of censored data

[JakaKokosar]

Issue

The curve feels crowded when there is a lot of censored samples.

Description of changes

Change the symbol for rendering censored samples (draw lines instead of circles).

Includes

• Code changes
• Tests
• Documentation

[JakaKokosar]

@mstajdohar is this better?

[mstajdohar]

Much better, thank you!

[mstajdohar]

An even better solution would be to display just the upper part of | (just the part above the curve), because you could see the shape of the curve more clearly. I don't know if that's possible, though.

[JakaKokosar]

@mstajdohar I can make it like this

But I'm not sure if it improves the visibilty of the curve if you zoom out.

[mstajdohar]

Perfect. Can you make the ticks half the size?

[JakaKokosar]

[mstajdohar]

Fabulous!