[Feature] Add a `queryComponent` helper function

[titouanmathis]

// Get the first instance of component with `config.name === 'Foo'`
queryComponent('Foo'): Foo | undefined;

// Get all instances of component with `config.name === 'Foo'`
queryComponentAll('Foo'): Foo[];

// Get the first instance of component with `config.name === 'Foo'` and with a CSS class `css-selector`
queryComponent('Foo(.css-selector)');

// Get the first instance of component with `config.name === 'Foo'` and which is mounted
queryComponent('Foo:mounted');
queryComponent('Foo:destroyed');
queryComponent('Foo:terminated');

// Limit the scope of the search to the given element
queryComponent('Foo', { root: document.documentElement });