PY-31647: support "MIDDLEWARE" in settings

Since 1.10 we use MIDDLEWARE instead of MIDDLEWARE_CLASSES

python/src/com/jetbrains/python/psi/impl/blockEvaluator/PyBlockEvaluator.java

@@ -28,6 +28,7 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.*;
+import java.util.stream.Collectors;
 
 /**
  * @author yole
@@ -133,6 +134,11 @@ public class PyBlockEvaluator {
     return value instanceof List ? (List)value : null;
   }
 
+  @NotNull
+  public List<String> getValueAsStringList(@NotNull final String[] name) {
+    return Arrays.stream(name).flatMap(o -> getValueAsStringList(o).stream()).collect(Collectors.toList());
+  }
+
   @NotNull
   public List<String> getValueAsStringList(String name) {
     Object value = myEvaluationResult.myNamespace.get(name);