v0.97RC3

Pre-release of version 0.97.

• Supports new networks with attention policy head (such as T79 or ap-mish networks)
• Adds major new feature for visual analysis of chess positions or games. See https://github.com/dje-dev/Ceres/blob/main/Graph.md
• Several small adjustments to play parameters (such as time control)
• Tournament Manager now supports variance reduction technique (force engine determinism)
• Various small fixes for use with tools such as Nibbler