Add TypeCasting and FunctionCommentType sniffs

Derived (shortened) version of my autofixer-branch Sniffs:
- https://github.com/dereuromark/cakephp-codesniffer/blob/master/Vendor/PHP/CodeSniffer/Standards/MyCakePHP/Sniffs/PHP/TypeCastingSniff.php
- https://github.com/dereuromark/cakephp-codesniffer/blob/master/Vendor/PHP/CodeSniffer/Standards/MyCakePHP/Sniffs/Commenting/DocBlockTypeSniff.php

Refs https://github.com/cakephp/cakephp/issues/3307 and the current CakePHP coding standards in the docs.
Indentation is off.