Refactored ColumnMenuUI into an extra base class called MenuUI. Both classes work the same, but the column can render submenus.
Imported the legacy ActivityMessage, ActivityMessageController and ActivityMessageUI from the Max Raider project. Then assets where refactored to use the new UI namespace.
Created UiManager methods to register, unregister, show and hide interface elements. Also created the UiSystemElementExample that implements the IUiSystemElement interface.
Removed the prefabs FloatingValuesPrefab and the FloatingHealthBarPrefab. Also removed references to them in the UiSystemModule loader. Both of this assets depended on code from the CharacterSystem module.
Removed the Dialogue folder containing the DialogueManager and SpeechBuble scripts. They require the NodeCanvas package which should not be require for this package.
