jun authored Mar 10, 2021 and Sara Arjona committed Mar 10, 2021

Since cm_info::customdata can be of any type, we need to cast it to an
array first before checking for custom completion rules. Otherwise,
an exception can be thrown (e.g. customdata has been set as an stdClass)

In all cases changes have been kept to a minimum while not making
the code completely horrible. For example, there are many instances
where it would probably be better to rewrite a query entirely, but
I have not done that (in order to reduce the risk of changes).

The $CFG->badges_site_backpack setting has been completely removed
because it's not required anymore. From now, the primary site
backpack will be the first one in the "Manage backpacks" list (so,
the one with lower sortorder value).

Before removing $CFG->badges_site_backpack setting, admins should be
able to re-order the existing site-backpacks (because then, the first
one will be treated as the default one).
This patch adds the sort order feature to the backpack list.

Use the custom completion implementation for mod_choice to test
completion_info::get_state() to cover the case where the completion
state is being determined from the custom completion condition.

* Update completion_info::get_data() to add other completion
information from a new method called get_other_cm_completion_data().
This allows the storage of the completion statuses of the following
completion rules to completion_info objects:
  - 'Students must receive a grade' completion rule.
  - Any custom completion rule defined by an activity.
This allows detailed completion information to be fetched for course
modules.
It also allows custom completion statuses to be cached which will help
reduce DB queries when fetching completion statuses.
* Update update_state() to fetch overall completion state from the
module's activity_custom_completion implementation. Falls back to the
*_get_completion_state() callback function.
* Update internal_set_data() to include the other cm completion data
in the updated cache data for the module instance.

Move the current logic for determining the completion status for the
"Student must receive grade" completion rule to a function so it cann
be reused.
Unit test included.

* Unit tests for completion_info::get_data() and
completion_info::internal_get_state are mocked which causes failures
with the new implementation. It's more straightforward and realistic
to generate real course and modules to test these methods.

Tests cover
 - get_overall_completion_state()
 - is_available()
 - validate_rule()
Tests don't cover
 - methods that rely on static methods such as:
   - is_defined()
 - static methods in the class because they can't be mocked
 - abstract methods that can be tested better by the plugins
   that extend activity_custom_completion such as:
   - get_state()
   - get_defined_custom_rules()
   - get_custom_rule_descriptions()

* Base class for defining an activity module's custom completion details

Currently admin_setting_configselect has lazy-loading support via a
callback function (so you don't have to make pointless single-use
classes for each unusual setting), but this is not present in other
similar types.

This commit adds identical support to
admin_setting_configmulticheckbox.

Setting "External backpack connection" has been moved from "Backpack
settings" to "Badges settings" in order to make easier to find and
configure it.
Some extra tests have been added to cover existing behaviour and
confirm is still working as expected.