Add transition to window buttons

[chaitunya]

This PR fixes #116076. It adds a 0.25-second-long transition to the window buttons for the Windows custom titlebar:

after.mp4

[sbatten]

@chaitunya in my testing, windows apps are not consistent about this. In fact, most store apps I have installed use no animation. Others use an animation but only to fade the red, not to activate it.

[chaitunya]

@sbatten I've also noticed that Windows apps aren't consistent about it, which is why I'm making this contribution.

I've done some testing with a screen recorder and slowing down the video, and realized that when activating, the transition length is 0.075s and when deactivating, the transition length is 0.15s. Should I switch the transition length to these values?

[sbatten]

@chaitunya yes please, which app are you basing this on in your video? It seems like it might be the new Edge, which would be my preference as well.

[chaitunya]

@sbatten I had originally tested File Explorer kind of hastily.

I had too much time on my hands today, so I just recorded Edge and slowed it down 60x, so each frame was one second.

Window.buttons.mp4

As you can see, the activation was 8 frames long and the deactivation was 13 frames long, so the timings should be about 0.13 seconds and 0.22 seconds, respectively.