Custom asset via plugin

[Dgzt]

This PR expands functionality of plugin system ^{1 2}. The purpose is that plugin can add new custom asset what runtime can load (via plugin's runtime module).

Changes:
Add new component type: NAVMESH

Add custom asset type.

New extension interfaces:

• AssetExtension:
  • void assetManager(AssetManager): Can handle custom assets via AssetManager.
• ToasterExtension:
  • void toasterManager(ToasterManager): Can handle toaster messages via ToasterManager.

Modified extension interfaces:

• ComponentExtension:
  • default Array<Component.Type> getSupportedComponentTypes() { return null }: Can handle where can create new component. For example: Create NavMesh component only on game object what contains terrain component.

Plugin's RootWidget additions:

• addTextField(TextFieldChangeListener): Adds textfield with change listener.

New subscribable editor events:

• ProjectChangedEvent: If the project changed.
• SceneChangedEvent: If the scene changed

Tested it with HTML and it works well.

You can try it with Mundus Example Project with Recast NavMesh plugin:
https://github.com/Dgzt/MundusRuntimeExample/tree/recast-navmesh-plugin
(use mouse buttons to select start and end positions, G for debug renderer)

Footnotes

1. https://github.com/JamesTKhan/Mundus/pull/268 ↩

2. https://github.com/JamesTKhan/Mundus/pull/289 ↩