Expandable Level Size from Level Editor

[TheJoeSmo]

Is your feature request related to a problem? Please describe. A clear and concise description of what the problem is. The only way to edit the level size is through the level header editor. This is unintuitive to newcomers and leads to a learning curve in expanding levels.

Describe the solution you'd like A clear and concise description of what you want to happen. Make it possible to edit the level size from the left and right and top and bottom for horizontal and vertical levels respectively directly from the level editor window. This would work in a similar regard as expanding generators, but with the entire level itself. This would allow for newcomers to directly edit the level size in an intuitive fashion, reducing the learning curve required to expand a level.

Additional context Add any other context or screenshots about the feature request here. When expanding a level leftward, the level should expand by a screen and push all blocks over 16 blocks and similarly for adding a screen for vertical levels.