Add DowngradeDeprecatedAttributeRector

[TomasVotruba]

New downgrade rule for PHP 8.4 #[\Deprecated] attribute.

Flips the attribute to a @deprecated annotation, docblock-way:

 #[\Deprecated(message: 'use someOtherMethod() instead', since: '1.5')]
 public function someMethod(): void
 {
 }

into:

 /**
  * @deprecated 1.5 use someOtherMethod() instead
  */
 public function someMethod(): void
 {
 }

• Handles methods, functions, class constants and enum cases.
• Reads message and since args (named or positional); multiline heredoc messages are collapsed to a single line.
• Registered in the downgrade-php84.php set.