Scientific Opinion on the safety and efficacy of 18 strains of Lactobacillus plantarum (DSM 23375, CNCM I‐3235, DSM 19457, DSM 16568, LMG 21295, DSM 16565, VTT E‐78076, CNCM MA 18/5U, NCIMB 30238, ATTC PTA‐6139, DSM 18112, ATCC 55058, DSM 18113, DSM 18114, ATCC 55942, ATCC 55943, ATCC 55944 and NCIMB 30094) as silage additives for all species