Fix Toolbutton lag in complex layouts

[Valer100]

Hi! This PR fixes an issue where hovering a ttk button with the Toolbutton style applied changes its state from hovered to normal with a delay after it is not hovered. This issue affects both light and dark themes.

Here's a screen recording when the issue happens:

Before.mp4

Here's a screen recording with the fix applied:

After.mp4

This problem was happening because the sprite used by the Toolbutton for its normal state had a different size (10x10) than the rest of the button states (20x20).

I tested this on Linux and it doesn't happen at all, but it happens on Windows.

[Valer100]

@rdbende Can you check this PR?

[Valer100]

It would also be nice to add a comment for new contributors at the beginning of both sprites_light.tcl and sprites_dark.tcl that they are auto-generated by spritesheet_generator.js and shouldn't be edited by hand. Only now I found out that they are auto-generated after experimenting with it in another branch.