Migrate populating local demo data through database.sql to using NetBox API

[henrybear327]

What would you like to be added?

Migrate populating local demo data through database.sql to through using NetBox API

Why is this needed?

When working on #167, we discovered that it's hard to maintain multiple versions of the database schema + data for each supported NetBox versions. After revisiting the current approach we are using, we figured these local demo data should be handled through API calls, so we don't tamper directly with the database and it will work by default with multiple NetBox versions.