Get Player Advanced Game Stats

Migrated from the following legacy PLG API route(s):

• player-advanced-game-stats: https://api.preciser.io/player/advanced-game/stats/*
• live-player-advanced-game-stats-test: https://api.preciser.io/player/live-advanced-game-test/stats/*

The legacy URL's organization segment is replaced by the League request header, allowing the same handler to select any authorized league database.