[WIP] Add support for Google One Tap sign-in

[asip]

This patch add support for Google One Tap sign-in.

Display Google One Tap
https://developers.google.com/identity/gsi/web/guides/display-google-one-tap?hl=en

Example:
https://github.com/asip/easel-back/blob/3d0ff7698b81b49ad041872fd0cb614bf2533d35/app/controllers/api/v1/oauth/sessions_controller.rb
https://github.com/asip/easel-back/blob/3d0ff7698b81b49ad041872fd0cb614bf2533d35/app/lib/sorcery/controller/submodules/external.rb

https://github.com/asip/easel-legacy/blob/ecbd5a97c2bac08dfecda24e0c536e5de4609aba/app/controllers/oauth/sessions_controller.rb
https://github.com/asip/easel-legacy/blob/ecbd5a97c2bac08dfecda24e0c536e5de4609aba/app/lib/sorcery/controller/submodules/external.rb

• Description of changes
• Update to CHANGELOG.md with short description and link to pull request
• Changes have related RSpec tests that ensure functionality does not break