Provide way to bind component to existing input

[mskocik]

Would be great to have this functionality for custom element. This would make it easy to integrate with 3rd party validation libraries and flows. Like Nette framework, where client-side validation definition is passed to rendered input

There are 2 ways to implement it:

• custom element with child input element
• or just input itself with ability to create component on focus (based some user-defined data attribute or any other way, like extending input with custom element)