Enable ESC to close/cancel dialogs

[SumatraPeter]

In Windows itself for example, the delete dialog can be closed/canceled simply by pressing ESC. In IG's delete confirmation dialog however ESC does nothing.

So it would be nice if IG's dialogs also responded to ESC to close/cancel them.

(Speaking of delete confirmation dialogs, while I like that IG's displays the full path to the file, it would be better if it also displayed the image dimensions and size like Windows' delete confirmation dialog does, which would be useful when one is in fullscreen mode with the titlebar and toolbar hidden.)

[d2phap]

Those are dialogs opened by MessageBox.Show() function do not support closing by ESC key. Most of them are for showing error message.

The rest can be closed by ESC, e.g. Rename dialog, Go to dialog, Custom zoom dialog,... I will need to replace the MessageBox by the custom dialog component.

[d2phap]

All dialogs in v9.0 beta 2 support closing / cancelling by ESC.