Baked data format for the client player tends to be large size

[miyanokomiya]

Current format includes 'id' too repeatedly because the priority of the nest is frames list > elements map.

[
  { id_1: {}, id_2: {} },
  { id_1: {}, id_2: {} },
]

In order to reduce those huge amount of duplication of id, the priority should be changed inside out.

{
  id_1: [{}, {}],
  id_2: [{}, {}],
}