In mysqli_native_moodle_database::raw_connect()

Implemented with moodle_read_slave_trait

Functionality is triggered by supplying config dboption['readonly'].
See config-dist.php for more info on supported dboptions.

pgsql and mysqli drivers are using this feature. Also added support for
connection timeout for these two drivers.

Or when a course category is moved/deleted

This is the external method for triggering the course module viewed event
and update the module completion status. Affects mobile app.

This WS should return access information required by an external client to check if and how to display the activity module.
Require for Mobile App