Create GameManager with SceneManagement systems

[jChicote]

Description

We will need to design the visualiser aspect to be modelled after a game.

Acceptance Criteria

• Can update and initialise
• Services and required components are loaded at start
• Gameobjects are rendering

Implementation

Create GameManager

• Will house the core components or any engine components.
• Services here will exist in a singleton pattern
• Will have reference to the current scene manager
• Functions here are strictly event based
• In-charge with configurating all game / visualiser aspects

Create SceneManager

• This component will keep track of the state of the game objects
• Note: This might hold reference to a statemanager if in-game entities exist + repositories
• Holds the main start and update loop. Which will be invoked by the main.js file
• In-Charge with configurating the scene and objects

[jChicote]

Scope change

The scene manager has been removed as there would be little functional difference between the GameManager and SceneManager currently.