Require @see annotations for plugin classes and methods

Nobody has claimed this yet.

### Rule
* A plugin class should have a `@see` annotation to the class(es) that it is intercepting.
* Each plugin method should have a `@see` annotation to the method(s) it is intercepting

### Reason
This rule would improve QOL for developers by providing a definitive link to what a plugin is intercepting. This can be especially useful for plugins that are intercepting more than one class.

### Implementation
An implementation has been written by Mediotype and can be modified for this standard. Our implementation checks:

* The rule checks only a class that has a namespace like `Vendor\Module\Model\Plugin\*` or `Vendor\Module\Plugin\*`
* The rule verifies that such a class has a class-level docblock containing a `@see` tag
* The rule checks only methods that are public and begin with before, after, or around (case sensitive)
* The rule verifies that such methods have a method-level docblock containing a `@see` tag

Start by locating the existing PHP coding-standard rule implementations and their tests; the issue does not name specific files or entry points. Use the stated plugin namespace, class-level and method-level docblock conditions, then add coverage showing that qualifying plugin classes and before/after/around methods require @see annotations.

Written by the indexing model from the issue text.