Allow Tiled2Rxdata to manage the volume and the pitch of the maps

MR Description

This MR allows Tiled2Rxdata to manage the volume and the pitch of the maps. This change is necessary to adapt to the new structure given by Studio.

Before:

bgm: 'music_bgm_name'

After:

bgm: {
  name: 'music_bgm_name',
  volume: 100,
  pitch: 100
}

Same for the bgs.

Before testing

• The project should be in 2.0.3 Studio version and migrate in 2.0.4 version (development version).

Tests to realize

• Check that change the music data in Studio is converted in RMXP (don't forget to launch PSDK)