Add $addCourseTool flag, so a course plugin will add an icon in the course home or not.

See BT#11080

main/inc/lib/course_home.lib.php

@@ -505,7 +505,7 @@ class CourseHome
                 //Other queries recover id, name, link, image, visibility, admin, address, added_tool, target, category and session_id
                 // but plugins are not present in the tool table, only globally and inside the course_settings table once configured
                 $sql = "SELECT * FROM $course_tool_table t
-                        WHERE category = 'plugin' AND c_id = $course_id $condition_session
+                        WHERE category = 'plugin' AND name <> 'courseblock' AND c_id = $course_id $condition_session
                         ORDER BY id";
                 $result = Database::query($sql);
                 break;

main/inc/lib/plugin.class.php

@@ -26,6 +26,8 @@ class Plugin
     public $isCoursePlugin = false;
     public $isAdminPlugin = false;
     public $isMailPlugin = false;
+    // Adds icon in the course home
+    public $addCourseTool = true;
 
     /**
      * When creating a new course, these settings are added to the course, in
@@ -461,6 +463,10 @@ class Plugin
             return true;
         }
 
+        if ($this->addCourseTool == false) {
+            return true;
+        }
+
         //Add an icon in the table tool list
         $table = Database::get_course_table(TABLE_TOOL_LIST);
         $sql = "SELECT name FROM $table

plugin/courseblock/CourseBlockPlugin.php

@@ -7,6 +7,7 @@
 class CourseBlockPlugin extends Plugin
 {
     public $isCoursePlugin = true;
+    public $addCourseTool = false;
 
     // When creating a new course this settings are added to the course
     public $course_settings = array(