Support Input/Output spread

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[ ] bug report => search github for a similar issue or PR before submitting
[x] feature request
[ ] support request => Please do not submit support request here, instead see https://github.com/angular/angular/blob/master/CONTRIBUTING.md#question

Current behavior

Currently each Input or Output must be explicitly declared in the component to allow its usage.

Expected behavior

I'd like to have any way to pass Inputs/Outputs to a component in the template without declaring them first. This is allowed in React with props spread and allows techniques like Higher Order Components.

<my-component [prop1]="prop1" {...otherInputs} ></my-component>

What is the motivation / use case for changing the behavior?

Declaring each Input/Output is a problem when wrapping some component to extend its behaviour or to hide the component when dealing with an external library. It requires mapping each of the wrapped component Inputs/Outputs and it's very tedious and error prone. Besides any change in the wrapped component API would require touching the wrapper component.