Rename to "OAuth 2.0"

To avoid confusion for end users, it'd be great if the human-readable name of this module would be changed from Simple OAuth to OAuth 2.0. Both on the d.o project page and in the *.info.yml file.

The project page description does explicitly mention this, but if the title both on d.o and in the Drupal UI were OAuth 2.0, it'd be far clearer :)

Sister issue at #2910602: Rename to "OAuth 1.0" + link to simple_oauth module for OAuth 2.0.