Prototype Interfaces removal from autocomplete

[yuriy-fix]

As a part of this task we should prototype removal of Interfaces with cluttering properties / attributes from types while persisting the properties that are necessary for proper component behaviour.

We should also list the properties that are manually added back for future reference. It will also enable us to provide clarifications on the reasons of adding specific property.

[web-padawan]

A few more properties to be removed: __cssBuild, _element and extends coming from ShadyCSS typings:

[tomivirkki]

The issue will be fixed by #167

The PR also fixes #137, #150 and #165

We should also list the properties that are manually added back for future reference. It will also enable us to provide clarifications on the reasons of adding specific property.

Note that the PR does not exclude properties from HTMLElement that are also included in React.HTMLAttributes

From the omitted HTMLElement properties, only autofocus is currently manually added back, because some Vaadin web components also have autofocus property (and it's not included in React.HTMLAttributes)

[rolfsmeds]

Closing as fixed by #167