MDL-69729 h5p: upgrade step to remove files in editor filearea

As temporary editor files have been moved from core_h5p/editor to
user/draft, they can be removed (to clean unused DB entries).

This is a backport of MDL-68909

lib/db/upgrade.php

@@ -2589,5 +2589,15 @@ function xmldb_main_upgrade($oldversion) {
         upgrade_main_savepoint(true, 2020061501.11);
     }
 
+    if ($oldversion < 2020061502.09) {
+        // Remove all the files with component='core_h5p' and filearea='editor' because they won't be used anymore.
+        $fs = get_file_storage();
+        $syscontext = context_system::instance();
+        $fs->delete_area_files($syscontext->id, 'core_h5p', 'editor');
+
+        // Main savepoint reached.
+        upgrade_main_savepoint(true, 2020061502.09);
+    }
+
     return true;
 }

version.php

@@ -29,7 +29,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$version  = 2020061502.08;              // 20200615      = branching date YYYYMMDD - do not modify!
+$version  = 2020061502.09;              // 20200615      = branching date YYYYMMDD - do not modify!
                                         //         RR    = release increments - 00 in DEV branches.
                                         //           .XX = incremental changes.
 $release  = '3.9.2+ (Build: 20201016)'; // Human-friendly version name