[RESEARCH] Consider slowly shifting various singleton managers to their own instances

[japtar10101]

Describe what to research into

Evaluate and create issues based on the effort it would take to shift the following singletons to their own script:

• SceneTransitionManager (issue [FEATURE] Migrate SceneTransitionManager to a project settings window  #46)
  • As a static class, and project setting window
• MenuManager
  • As its own prefab
• WebLocationChecker (issue [FEATURE] Migrate WebLocationChecker to a project settings window #47)
  • As a static class, and project setting window
• GameSettings
  • As a static class, and project setting window
• CameraManager
  • As its own prefab
• TranslationManager (issue [FEATURE] Migrate localization to a project settings window #25)
  • As a static class, and project setting window
• SocialManager
  • As a static class, and project setting window
• TimeManager
  • As a static class, and project setting window
• AudioMixerReferences
  • As a static class, and project setting window

Additional context

Carry-over from the old Bitbucket Mercurial project:
https://bitbucket.org/OmiyaGames/hg-template-unity-project/issues/66

[japtar10101]

For some of these Singletons, converting them into a SettingsProvider might be the best choice.