Implement assignable user permissions

[jacobmartinez3d]

Currently there is no enforcement of permissions with regard to database CRUD operations and/or filesystem directories. User's in the magla ecosystem should have varying levels of permissions based on their role's in the pipeline.

Example:

• Artists should be able to perform CRUD operations on their personal MaglaDirectory records but not those associated to tools or shots or projects.
• Versioning up a shot currently requires access to magla.core.root.version_up so, access to that method could feasibly be distributed separately from the other main CRUD functions and given to artists, or leads.
• There should be a root admin privilege set which is reserved for the user responsible for the initial setup and configuration of magla and postgres. These permissions would give total control over anything.