In this commit, the following improvements were made to the mod_lti Behat tests:
* Replaced manual steps with data generators to set completion.
* Eliminated unnecessary user and course enrolments data generation as some tests can be performed as an admin.
* Removed the @javascript tag from non-JS tests.
* Updated the LTI data generator to generate an internal Moodle URL in the toolurl field, enabling the use of XML files.