More granular query methods with predicate function and/or props

It would be great to be able to do more granular searches by passing a props or function argument to query methods):

``` js
// Given the following tree:

tree.findComponent('Widget', { title: 'First' });
// =>

tree.findComponent('Widget', { active: false });
// =>

tree.findComponent('Widget', (props) => props.count > 25);
// =>
```

On a related note, it would be nice if there was an `everySubTreeLike` method analogous to `findComponentLike` and more "plural" methods to return multiple nodes/components e.g. `findNodes`/`findComponents(Like)`/whathaveyou.

Start by reviewing the existing findComponent and findComponentLike query methods to understand their current matching behavior. Clarify whether predicate and props matching, everySubTreeLike, and plural query methods are all in scope, then define tests for the agreed API and its expected returned nodes or components.

Written by the indexing model from the issue text.