Refactor having multiple dictionaries of values to a dictionary of a structure of values.
Refactor having multiple dictionaries of values to a dictionary of a structure of values.

This enables to have access to the legal_actions, from `info_state_str`. When creating the object, we now also always do a full pass on the tree. A next CL will give access to the Current policy.

PiperOrigin-RevId: 268912958
Change-Id: I1255c391d330ed97f173738145cbd67970c3c31d

deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel