[DO NOT MERGE! Work is parked currently] [MTT-8685] Feat: UIToolkit for BossRoom: PostGame UI

[Elfi0Kuhndorf]

Description

Adjusting scripts and creating assets to transform the UI elements within the Post Game scene to UIToolkit. This includes the SettingsPanelCanvas and the PostGameUICanvas

Issue Number(s)

https://jira.unity3d.com/browse/MTT-8685

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
• [x] Pull request has a meaningful description of its purpose
• [x] All commits are accompanied by meaningful commit messages
• [x] JIRA ticket ID is in the PR title or at least one commit message
• [x] Include the ticket ID number within the body message of the PR to create a hyperlink
• [ ] An Index entry has been added in readme.md if applicable

[unity-cla-assistant]

All committers have signed the CLA.