Materials Utils: Update to version 1.0.4

Bump version to 1.0.4
Some style tweaks
Refactor some of the if - else loops
Correct some of the tooltips
Various UI tweaks

Improvements:
- Introduce a pop-up menu for assigning and selecting materials
- Add support for removing empty material slots for non mesh objects
- Activate the material slot more reliably after creation, applying
- Texture Renamer: add option for rename all objects in the data
- Warning Messages: better formatting of console prints