GUI: An option to decrease speed of/add delays to AI plays

Being Fatal Pushed is barely noticeable while playing with AI :). This issue actually affects most of important board state changes and results in a player being forced to try to grok what just happened from log (which is usually not an easy task thanks to #13318 :) )

Start by tracing the GUI handling of AI plays and the important board-state changes described in the issue, then compare what is visible in the log and review issue #13318 for related context. Done means players can configure slower AI actions or added delays so significant state changes are noticeable during play.

Written by the indexing model from the issue text.