Fix CapsLock everywhere

[JoelEinbinder]

Is it being treated as a modifier?

[yury-s]

It is, see Source/WebCore/platform/PlatformEvent.h line 78

[JoelEinbinder]

I think we fail to emulate https://www.w3.org/TR/uievents/#dom-keyboardevent-getmodifierstate in all browsers. I should add a test.

[pavelfeldman]

I'll close this as won't fix and wait for the feature request from the field.