Published: September 8, 2011 Publication: Daily News By Mark Morales Angry parents at a Flatbush middle school are hoping a lawsuit against the city will stop a charter school from squeezing into the school’s building for good. The Explore Charter school has been holding classes in the building on Parkside Ave. – home to Parkside Preparatory Academy – since late August. A lawsuit filed by parents against the city’s Department of Education is an attempt to undo the co-location