Anst/improvements

[achimmihca]

What does this PR do?

This is PR fixes some issues and prepares the next release.

Versioning

• The BuildInfoGenerator adds the commit hash of git to the VERSION.txt file (e.g. 5e07588). And the MainScene shows this next to the regular semantic version number.
  • I realized that some automatic mechanism is needed to tell builds apart. The previous build-timestamp approach is not optimal, because the same code base could be build at a different time. The commit hash is a better automatic identifier for the version.
• The regular semantic version number in VERSION.txt is now taken from the ProjectSettings.
  • This way, only one version must be adjusted.
  • ProjectSettings.bundleVersion is probably more important because this could affect other places, such as Google Play Store, App Store, etc. Thus, this value is copied to VERSION.txt and not vice versa

Refactoring

• Many files changed because I removed List<IDisposable> and instead use UniRx' extension method AddTo(GameObject)
  • The extension method calls Dispose() in OnDestroy of the GameObject, just like before

fixes

• The (dis)connect event of a companion app was not handled in some places (e.g. SongSelect). This has been improved.

[achimmihca]

@basisbit any news on this PR?