Merge AlienPAK and CommandsEditor

[MattFiler]

In an ongoing effort to make the tools more streamlined, I would like to merge the functionality that AlienPAK has for modifying textures/materials/models into the script editor. This will not only make the tools simpler to use, but also mean there are less conflicts between OpenCAGE editors while modifying assets and scripts simultaneously.

This should take the form of porting the functionality for:

• [x] Displaying textured models
• [ ] Viewing and modifying material data
• [ ] Viewing and importing/exporting/deleting textures
• [ ] Viewing and importing/exporting/deleting models ... and when it is implemented, the ability to port models/materials/textures between levels - which should be done alongside porting composites.

Will then need to think about where the UI and animation tools go - perhaps as just an additional tools dropdown in the script editor? Animation tool improvements are covered by #278.

[MattFiler]

Material viewer is now on staging, without modification support