This ignores unhandled mouse clicks for the window buttons. Right now
right-clicking on the window buttons animates them as if some action
were to occur when the mouse button is released.
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This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
Button now can handle middle and right clicks.
Added 2 new handlers in button class: on_right_click for Right mouse
button and on_middle_click for middle mouse button.
Added functionality to vertically maximize window with middle mouse
click on the maximize window button.
Also added a way to vertically maximize window by resizing window
height-wise lower than the maximum window height.
