- Revert unnecessary primary_active_tab setters
- Modify the navigation nodes to never change text based on default homepage
- Make sure a tab is set active

Quiz completion settings are only validated if they are unlocked.
Undefined behaviour in the forms API results in the completion
settings 'require passing grade' and 'completion attempts exhausted'
not being sent to the process options function if completion
settings are locked. This resulted in the completion attempts
exhausted setting being disabled whenever the quiz was saved
as it did not detect the require passing grade setting.
This changes the behaviour so that validation is only performed
if the completion settings are unlocked.
A behat test is included to ensure the setting does not change.

The new get_safe_orderby() and get_safe_orderby_multiple() methods
provide a centralised safe way for user submitted sorting values to be
incorporated into SQL ORDER BY. They do this by removing the need for
user submitted data to pass in any SQL and not allowing arbitrary
column values, instead using string keys which map to a predefined
list of allowed sortable columns.

Checks if a form element has attributes before
trying to get the default value. This fixes
an error when trying to get the default value
for a frozen group which does not have the
attributes array.

David Matamoros authored Nov 05, 2021 and Paul Holden committed Nov 11, 2021

Co-authored-by: Paul Holden <paulh@moodle.com>