feat: improvements to child scene loader

[SamuelBellomo]

Description

Removing config object from builds and scene hierarchy. They are now only editable through menu. (still saved in scene, but invisible). This way there's no more garbage in game scenes and this config is still saved per scene.

Adding automatic expand of child scenes when loading root scene.

Issue Number(s)

TODO

• Utilities uses the word "boss room" its menu, this isn't great for something that should be reusable.

Contribution checklist

• Tests have been added for boss room and/or utilities pack
• Release notes have been added to the project changelog file and/or package changelog file
• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• JIRA ticket ID is in the PR title or at least one commit message
• Include the ticket ID number within the body message of the PR to create a hyperlink