Added the ability to query by widget id

[BrooksPatton]

I added a QueryFilter option by_id which takes in a WidgetId. This is helpful especially if we want to focus on our own component from our component.

Example, we check if we've been clicked on, and if so focus on ourselves.

I didn't see any automated tests in this section so I didn't add any.

[JustusFluegel]

Quick summary i wrote on @BrooksPatton 's stream for this pr, just posting it here for completeness :)

Summary

• Adds DefferedComponents::by_id(&mut self, WidgetId) -> QueryBuilder<'_> method
• Adds QueryBuilder<'_>::by_id(self, WidgetId) -> Self method

In support of that

• Adds Filter:Id(WidgetId) filter variant

Motivation

Some actions (e.g. focus) are only available for deferred components, an sometimes we wish to execute them on the current or a child component. As such the following pattern seems desirable:

let my_id = context.widget_id; 
// or
let my_id = children.components().by_name("...")....; 

context.components.by_id(my_id).focus()

[BrooksPatton]

Thanks Justus!