Show setup wizard after activation via Add New Plugin screen

[brianhogg]

Description

The current method of using a transient to decide if a redirect should happen isn't reliable since a transient could disappear after creation. With WP 6.5 using AJAX for plugin activations, it needs to be reliably around longer.

Fixes #2622

How has this been tested?

Manually

Types of changes

Checklist:

• [ ] This PR requires and contains at least one changelog file. <!-- To create a changelog yml file: npm run dev changelog add -- -i and follow the prompt. See also: https://github.com/gocodebox/lifterlms/blob/trunk/packages/dev/README.md#changelog-add -->
• [ ] My code has been tested.
• [ ] My code passes all existing automated tests.
• [ ] My code follows the LifterLMS Coding & Documentation Standards.