refactor: material inspector window as ADocumentWindow

[iMeaNz]

Objective

For now, the Material inspector window is handled directly inside the Inspector Window.
Since it is still a entirely new window, it should be handled like the others and derive from the ADocumentWindow class.
We should use the WindowRegistry to get the necessary data for its handling.

Acceptance Criteria

• 1. The WindowRegistry class should be implemented in order to be able to retrieve the necessary data
• 2. The DockingRegistry class should be implemented in order to be docked properly when first rendering it
• 3. The Material Inspector window should be handled like any other

Dependencies

No response

Technical Details

No response

Type

Editor