feat: Single dimension zooming

[MickHarrigan]

Adds the ability to zoom a plot in only the x or y direction if the user created "box" is very thin.
This functionality is similar to that of other plotting libraries such as plotly.

Creates a buffer around the point where the drag begins that determines the type of zoom. Adds 2 new types of zoom, horizontal and vertical, while still supporting typical box zoom.
Single direction zooming is only valid if proportional axes (data_aspect) is off.

Here is a quick example in the demo showing how it works.
https://github.com/user-attachments/assets/cd21823f-cfdd-4874-a4cd-08ab6b307dab

[bircni]

could you add an example?

[MickHarrigan]

What should the example show that the Lines demo example doesn't show already?

[michalsustr]

This is a great feature and exactly what I wanted to add to the library, thank you!

Based on the video, I think it is visually clearer if the whole vertical/horizontal span is highlighted, similar to screenshot in #152
Do you think you can update the PR to do this for single dimension zooming?

[MickHarrigan]

@michalsustr I should be able to get something to align this with the span impl sometime this week hopefully. Thanks for the feedback!

[michalsustr]

Great, thank you!