Bind button command to <ButtonRelease-1> for native-like behavior

[Riki-Sternbuch]

This change updates CTkButton to trigger its command only on instead of , matching standard OS behavior and improving UX.

[FedericoSpada]

Hi,
I like the idea a lot since it gives the user the possibility to change their mind before the callback is actually called.

I would also move the click animation after the Left button has been released. For this reason, starting from the original code, I would suggest modifying "Button-1" with "ButtonRelease-1" every time it appears.
Then, you can update the _clicked() function to check whether the mouse is still inside the button.

Regarding this last aspect, I think that your code is not working properly: the callback has been assigned to multiple objects (canvas, label, image), so the "event" parameter provides its x and y values with respect to different reference frames. If you always compare them with canvas dimensions, sometimes, it happens that the callback is not triggered.
To write the perfect condition, I think that you have to play with self.winfo_pointerx() and self.winfo_rootx().