[TS] Fix generation of struct members in object api (#7148)

* Fix C/C++ Create<Type>Direct with sorted vectors

If a struct has a key the vector has to be sorted. To sort the vector
you can't use "const".

* Changes due to code review

* Improve code readability

* Add generate of JSON schema to string to lib

* option indent_step is supported

* Remove unused variables

* Fix break in test

* Fix style to be consistent with rest of the code

* [TS] Fix reserved words as arguments (#6955)

* [TS] Fix generation of reserved words in object api (#7106)

* [TS] Fix generation of object api

* [TS] Fix MakeCamel -> ConvertCase

* [TS] Add test for struct of struct of struct

* Update generated files

* Add missing files

* [TS] Fix query of null/undefined fields in object api

tests/MyGame/Example/StructOfStructsOfStructs.lua

@@ -0,0 +1,49 @@
+--[[ MyGame.Example.StructOfStructsOfStructs
+
+  Automatically generated by the FlatBuffers compiler, do not modify.
+  Or modify. I'm a message, not a cop.
+
+  flatc version: 2.0.6
+
+  Declared by  : //monster_test.fbs
+  Rooting type : MyGame.Example.Monster (//monster_test.fbs)
+
+--]]
+
+local flatbuffers = require('flatbuffers')
+
+local StructOfStructsOfStructs = {}
+local mt = {}
+
+function StructOfStructsOfStructs.New()
+  local o = {}
+  setmetatable(o, {__index = mt})
+  return o
+end
+
+function mt:Init(buf, pos)
+  self.view = flatbuffers.view.New(buf, pos)
+end
+
+function mt:A(obj)
+  obj:Init(self.view.bytes, self.view.pos + 0)
+  return obj
+end
+
+function StructOfStructsOfStructs.CreateStructOfStructsOfStructs(builder, a_a_id, a_a_distance, a_b_a, a_b_b, a_c_id, a_c_distance)
+  builder:Prep(4, 20)
+  builder:Prep(4, 20)
+  builder:Prep(4, 8)
+  builder:PrependUint32(a_c_distance)
+  builder:PrependUint32(a_c_id)
+  builder:Prep(2, 4)
+  builder:Pad(1)
+  builder:PrependInt8(a_b_b)
+  builder:PrependInt16(a_b_a)
+  builder:Prep(4, 8)
+  builder:PrependUint32(a_a_distance)
+  builder:PrependUint32(a_a_id)
+  return builder:Offset()
+end
+
+return StructOfStructsOfStructs