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/uploaduser/user_form.php

@@ -35,7 +35,7 @@ require_once($CFG->dirroot . '/user/editlib.php');
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class admin_uploaduser_form1 extends moodleform {
-    function definition () {
+    function definition() {
         $mform = $this->_form;
 
         $mform->addElement('header', 'settingsheader', get_string('upload'));
@@ -90,7 +90,7 @@ class admin_uploaduser_form1 extends moodleform {
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class admin_uploaduser_form2 extends moodleform {
-    function definition () {
+    function definition() {
         global $CFG, $USER;
 
         $mform   = $this->_form;