The name of the database to open.
The database version to open.
A function that migrates the database schema, called
on onupgradeneeded only. Receives the database, the previous version
(0 for fresh installs), and the upgrade transaction — the transaction is
required for data migrations (cursor/update on existing stores).
A promise that resolves to the database instance.
Opens an IndexedDB database and increments the reference count. Handles global object detection and callbacks.