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.

analytics/classes/calculable.php

@@ -79,7 +79,7 @@ abstract class calculable {
      *
      * @return \lang_string
      */
-    public static abstract function get_name() : \lang_string;
+    public static abstract function get_name(): \lang_string;
 
     /**
      * The class id is the calculable class full qualified class name.