Remove access to the global gArgs for these arguments and replace them by adding fields to the existing ChainstateManager Options truct.

This should eventually allow users of the ChainstateManager to not rely on the global gArgs and instead pass in their own options.

Note that there is no change in behavior for automatic unparking, as the avalanche pointer arg passed to ActiveBestChain is non-null only if args.GetBoolArg("-avalanche", AVALANCHE_DEFAULT_ENABLED) (see init.cpp where node.avalanche is initialized).

ninja all check-all