stats.ncaa.org migrated team statistics from the franchise-centric
/team/{team_id}/stats?... query form to a season-team resource at
/teams/{season_team_id}/season_to_date_stats. The season_team_id is
year-specific and is not the franchise team_id. This helper resolves it
by reading the still-working roster page
(/team/{team_id}/roster/{season_id}) and extracting the "Team Statistics"
link it points to.
.ncaa_resolve_season_team_id(team_id, season_id, ...)A length-1 character season-team id, or NA_character_ if the roster
page could not be read (e.g. challenged) or the link was not found.
Franchise team id used by the NCAA site.
Season id from load_ncaa_baseball_season_ids() (the id
column), i.e. the value the roster URL expects.
Passed through to request_with_proxy() (e.g. proxy).