[Java] Fix SchemaDef struct full name in Java

Make the full name use the IDL namespace (as in C++ and C#). Previous
attempt [https://github.com/Microsoft/bond/pull/567] was broken during CR.

compiler/src/Language/Bond/Codegen/Java/Class_java.hs

@@ -491,7 +491,7 @@ public class #{typeNameWithParams declName declParams}#{maybe interface baseClas
 
         @Override
         public final String getQualifiedName() {
-            return "#{qualifiedDeclaredTypeName java s}";
+            return "#{qualifiedDeclaredTypeName idl s}";
         }
 
         @Override
@@ -531,6 +531,7 @@ public class #{typeNameWithParams declName declParams}#{maybe interface baseClas
     }
 }|]
             where
+                idl = MappingContext idlTypeMapping [] [] []
                 interface = [lt| implements org.bondlib.BondSerializable|]
                 baseClass x = [lt| extends #{javaType x}|]
                 publicFieldDecl Field {..} = [lt|public #{javaType fieldType} #{fieldName};|]

compiler/tests/generated/basic_types_nsmapped_concatenated.java

@@ -81,7 +81,7 @@ public class BasicTypes implements org.bondlib.BondSerializable {
 
         @Override
         public final String getQualifiedName() {
-            return "nsmapped.BasicTypes";
+            return "tests.BasicTypes";
         }
 
         @Override