Ability to programmatically import device types

[abhi1693]

Provide a way to either import the device types using API or other programmatic calls.

In my workflow, I get the device type from the bare metal server but if it does not exist in the database, the execution fails. At this point, someone has to import the type manually using your plugin. This is a cumbersome task to do when most of the other tasks are running automatically to update the information on NetBox.