Remove dependency on Lookup

Description

The consent operation and template are using a lookup connection to only get the logged in users displayName.

This could be retrieved from the Google Workspace API's fullName field instead would remove a dependency on lookup by returning one to the API Gateway (that it is already dependent on).

Functionality for retrieving the Google user was removed in 1c68e57c so should be easily restorable.

Alternatively, social auth will return the name(s) from the oauth login.

Task list

• Either:
  • Restore the functionality to get the user from Google Workspace API
  • Use the Google's fullName in place of Lookup's displayName
  • Ensure tests cover restored functionality and its usage
• Or:
  • Retrieve the user's name from the social auth populated django user
• Remove now unused lookup code and tests

Acceptance criteria

• Login and Consent app is no longer dependent on Lookup