Update organization extensions to disallow modifying label
The current organization extensions will allow the user to modify the organization label attribute; however, this should be a read-only field, since changing changing it has negative implications on other aspects of the system (e.g. repo names).
This issue is to update the organization model to disallow this.
Fixes #6946: Update organization to disallow modifying label
Changed code to disallow updating any entity's label at the model level