Duplicate material names

[volkerblum]

Since we're already here today, Shreyas and I found that it is possible to create duplicate material names (same name, different identifier).

This should not be possible and we need to create a fix to prevent this.

At the same time, once a material is duplicate and the duplicate is deleted, it appears that the current DB instances still remembers the "new" ID rather than the ID of the original material.

We need to look into how to address this.

Thank you!
tagging @Eisenl10 @rayanc72 (who are already aware by separate email but should have logged here instead)