Joined Cases T-722/15 to T-724/15: Judgment of the General Court of 12 December 2018 — Interessengemeinschaft privater Milchverarbeiter Bayerns and Others v Commission (State aid — Aid for the Bavarian dairy sector — Financing of milk quality tests — Decision declaring the aid to be incompatible with the internal market — Right to participate in the administrative procedure — Article 108(2) TFEU — Article 6(1) of Regulation (EC) No 659/1999)