Make calculate(Horizontal/Vertical)ContentSize in Component

[kikugie]

Motivation

Complex parent components may need to know how much space their children need before arranging them.
Currently this can be achieved by inflating each child, seeing how much space they take with no restrictions and reinflating them with properly calculated space.

However, this invokes inflate on children twice, which may contain expensive calculations, such as rearranging nested child components or calling overridden applySizing, which is useful for caching rendering parameters on custom components.

Solution

This can be solved by asking how much space each child needs beforehand, without modifying them.
BaseComponent already has such functionality with determine(Horizontal/Vertical)ContentSize methods,
but they are marked as protected and not available in the base Component type.

This PR moves said methods to the Component interface and updates overridden implementations.

[kikugie]

Update

Putting determine(Horizontal/Vertical)ContentSize in Component creates a compiler error for all inheritors requiring it to be public.
I've made calculate(Horizontal/Vertical)ContentSize in Component for this purpose.
BaseComponent overrides those to return the result of the overriden determine(Horizontal/Vertical)ContentSize without breaking compatibility.
(This is some OOP shenanigans, if I may say so)