EDINBURGH, June 27 (Reuters) - European stocks were seen steady to slightly higher on Friday, but were still set for their biggest weekly drop since April to pull back from multi-year highs, knocked back by global growth concerns. The pan-European FTSEurofirst 300 .FTEU3 is down 1.7 percent for the week, and looks set to snap a 10-week winning streak, which had been its longest since