Update table_sql to support dynamic initials bar

Take a course with a number of users enrolled in it View the participants page Ensure that the page has finished loading Click each of the column sorting links in turn Confirm that the sort order was updated, and the page did not reload Confirm that you can sort correctly in both directions Use each of the initials bars to filter the users Confirm that the table updated and the page did not reload Confirm that the initials bar worked as expected (i.e. you selected A as a first iniitla, and only those users whose name begins with A were shown) Use the initials bar to show a combination with no users (i.e. First name beginning with Z and you have no users whose name begins with Z) Confirm that the "Nothing to display" message is shown Select the "All" options Confirm that the table was shown, and the page did not reload Open user/classes/participants_table.php in your preferred editor Find the out function Edit the file to et $useinitialsbar = false; at the top of the function, i.e.: public function out($pagesize, $useinitialsbar, $downloadhelpbutton = '') { $useinitialsbar = false; global $CFG, $OUTPUT, $PAGE; View the participants page again Confirm that the initials bar was not shown Attempt to sort the table again using the column sort links Confirm that the table still updates and that the page does not reload when you do so