playerset can add players from other competition

[Mushroom-MSL1L]

as title GET : api/playerset/elimination/medal will exclude illegal data

[Otmeal]

10/5 UI不允許這個問題出現。

[Mushroom-MSL1L]

11/9：這有資安疑慮喔，這個database沒有一大塊東西寫好。