MDL-65292 style: Fix all function declarations white space

This has been generated running the following Sniffs, all
them part of the Moodle's CodeSniffer standard:
- PSR12.Functions.ReturnTypeDeclaration
- PSR12.Functions.NullableTypeDeclaration
- moodle.Methods.MethodDeclarationSpacing
- Squiz.Whitespace.ScopeKeywordSpacing

All them are, exclusively, about correct spacing, so the changes
are, all them, only white space changes.

Only exceptions to the above are 3 changes what were setting the
return type in a new line, and, when that happens, the closing
parenthesis (bracket) has to go to the same line than the colon.

admin/tool/monitor/classes/privacy/provider.php

@@ -52,7 +52,7 @@ class provider implements
      * @param  collection $collection An object for storing metadata.
      * @return collection The metadata.
      */
-    public static function get_metadata(collection $collection) : collection {
+    public static function get_metadata(collection $collection): collection {
         $toolmonitorrules = [
             'description' => 'privacy:metadata:description',
             'name' => 'privacy:metadata:name',
@@ -90,7 +90,7 @@ class provider implements
      * @param  int $userid The user ID.
      * @return contextlist The list of context IDs.
      */
-    public static function get_contexts_for_userid(int $userid) : contextlist {
+    public static function get_contexts_for_userid(int $userid): contextlist {
         $params = ['useridrules' => $userid, 'useridsubscriptions' => $userid, 'contextuserrule' => CONTEXT_USER,
                 'contextusersub' => CONTEXT_USER];
         $sql = "SELECT DISTINCT ctx.id

admin/tool/monitor/classes/rule_form.php

@@ -40,7 +40,7 @@ class rule_form extends \moodleform {
      * Mform class definition
      *
      */
-    public function definition () {
+    public function definition() {
         global $PAGE;
 
         $mform = $this->_form;