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.

customfield/classes/data.php

@@ -47,7 +47,7 @@ class data extends persistent {
      *
      * @return array
      */
-    protected static function define_properties() : array {
+    protected static function define_properties(): array {
         return array(
                 'fieldid'        => [
                         'type' => PARAM_INT,