Catalog widget warnings

[kimhornung]

When using the Scorm Cloud Catalog Widget with WP_DEBUG enabled, warnings will appear in the debug.log file.
This happens because some functions in the ScormCloudPlugin class are not marked static.
Also, a warning about wpdb->prepare being used incorrectly appears.

Steps to reproduce

1. Add the following lines to wp-config.php to enable WP debug

define('WP_DEBUG', true);
define('WP_DEBUG_DISPLAY', false);
define('WP_DEBUG_LOG', true);

2. Add the "Scorm Cloud Catalog Widget" to a sidebar or footer area

3. Open the website

Result:
The following warnings appears in the log file:

[09-Nov-2022 08:48:11 UTC] PHP Deprecated:  Non-static method ScormCloudPlugin::loadAllCourses() should not be called statically in <webroot>/scormcloud/ui/scormcloudcatalogwidget.php on line 53
[09-Nov-2022 08:48:11 UTC] PHP Notice:  Function wpdb::prepare was called <strong>incorrectly</strong>. Unsupported value type (array). Please see <a href="https://wordpress.org/support/article/debugging-in-wordpress/">Debugging in WordPress</a> for more information. (This message was added in version 4.8.2.) in <webroot>/wp-includes/functions.php on line 5831

PS: The problem with the wpdb->prepare() call is that OBJECT was passed as a 3rd parameter to the function. Instead, OBJECT should be passed to the wpdb->get_row() call.