[BUG] Texture Groups disappear when you reload the project #407

Describe the bug
When you create a Texture Group in an Animated Java Blueprint, if you reload the app or the project, the Texture Group disappears. The textures that were inside don't disappear, instead they move outside of the folder. This doesn't happen in regular Blockbench.

To Reproduce
Steps to reproduce the behavior:

1. Create an Animated Java Blueprint.
2. Create a Texture Group.
3. Save the project and close it.
4. Open the project and see how the Texture Group is missing.

Expected behavior
Texture Groups should be saved with the project and reloaded again when you open the project.

Desktop (please complete the following information):

• OS: Windows 10
• Version: 2009

Additional context
Seems like an Animated Java bug, because it doesn't happen in regular blockbench projects.