Support binary search for struct in cpp (#4245)

* Support binary search for struct in cpp

CreateVectorOfSortedStruct is provided for convenience.

* fix continuous-integration error

* add generated files

* compile Ability.cs in csharp test

* compile Ability.cs in csharp

* modify according to code review

tests/MyGame/Example/Ability.py

@@ -0,0 +1,23 @@
+# automatically generated by the FlatBuffers compiler, do not modify
+
+# namespace: Example
+
+import flatbuffers
+
+class Ability(object):
+    __slots__ = ['_tab']
+
+    # Ability
+    def Init(self, buf, pos):
+        self._tab = flatbuffers.table.Table(buf, pos)
+
+    # Ability
+    def Id(self): return self._tab.Get(flatbuffers.number_types.Uint32Flags, self._tab.Pos + flatbuffers.number_types.UOffsetTFlags.py_type(0))
+    # Ability
+    def Distance(self): return self._tab.Get(flatbuffers.number_types.Uint32Flags, self._tab.Pos + flatbuffers.number_types.UOffsetTFlags.py_type(4))
+
+def CreateAbility(builder, id, distance):
+    builder.Prep(4, 8)
+    builder.PrependUint32(distance)
+    builder.PrependUint32(id)
+    return builder.Offset()