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/httpsreplace/classes/privacy/provider.php

@@ -40,7 +40,7 @@ class provider implements \core_privacy\local\metadata\null_provider {
      *
      * @return  string
      */
-    public static function get_reason() : string {
+    public static function get_reason(): string {
         return 'privacy:metadata';
     }
 }