Go to symbol referenced in docblock

```php
/**
 * @param A<>|B $p
 */
function f($p): void {}
```
Assume the cursor is in the '<>' position. It would be great if PHPActor would be able to navigate (and, ideally, support all other features like context menu from that point) to `A`s definition, like it can when `A` is referenced in executable code.

Currently it complains about 'symbol type <unknown>'