MDL-38547 behat: New tests

According MDLQA-1597, MDLQA-1598,
MDLQA-1599, MDLQA-1600 and MDLQA-1601
MDL-38547 behat: New generic steps definitions

For advanced users as specified in the step
description, they can be used to match any locator
using any selector type
MDL-38702 theme_mymobile: Replaced missing theme setting to disable CSS Optimiser.

The missing setting was a regression casued by MDL-33357.
MDL-38700 course: add tests for moveto_module()

* Test visibility when moving around hidden sections
* Test for visiblity changes when moving around in the same sections.
MDL-38700 course: only change visibility if a module moves to a different section
MDL-38713 course: correctly set visibleold on mod creation

Remove uncessary set of visibleold in the form
MDL-38486 behat: Course's topics highlighting steps definitions
MDL-38486 behat: New test

Section highlighting can be turned off
correctly using the toggle highlighting
icon. According to MDLQA-1591, MDLQA-1592,
MDLQA-1593, MDLQA-1594 and MDLQA-1595
MDL-38499 behat: New test

The show/hide section icon functions
correctly. According to MDLQA-1579,
MDLQA-1580, MDLQA-1581, MDLQA-1582
and MDLQA-1583.
MDL-38499 behat: Steps definitions for section visibility management
MDL-38437 behat: Step definition to add a discussion
MDL-38437 behat: Behat feature for mod_forum

Basic add an activity, MDLQA-2 (students
can edit or delete their forum posts within
a set time limit).
MDL-38439 behat: New test

According to MDLQA-3, a teacher can
set one of 3 possible options for
tracking read forum posts.
MDL-38475 behat: Step definition to reply a discussion
MDL-38475 behat: New test

According to MDLQA-5, students can choose
from 4 discussion display options and their
choice is remembered.
MDL-38476 behat: New test

According to MDLQA-9, in a single
simple discussion forum only teachers
can start discussions.
MDL-38477 behat: New test

According to MDLQA-16, teachers can edit
or delete any forum post.
MDL-38621 behat: New test

According to MDLQA-1172, course short
names may be displayed on the list of
courses page.
MDL-38620 behat: New test

According to MDLQA-1175; test
removed from repository_upload as
is included in MDLQA-1175 test
MDL-38620 behat: Modified upload_users.csv fixture

Including course and group enrolments