Dynamically increase space for validator list

[AgeManning]

When checking which validator indexes the box only shows me three, and its a bit tedious to scroll through, especially when there is extra room on my screen.

If possible, it would be good to fill the vertical space in the screen to give me more visibility over validator indicies.

See:

[AgeManning]

I have the same thing happening for consolidating validators. When there are many I have to scroll through the box, when there is a lot of extra space vertically it could fill instead.