Update HTMLView TS definitions to support class components #338

Currently, HTMLView's definitions specify the following props to accept function components only:
NodeComponent, RootComponent, TextComponent

However, the source code that uses these props, only uses destructuring assignment to extract these from the HTMLView's props, and then creates these components as JSX tags:

RootComponent:

This approach is compatible for use with both functional and class components.
In fact, I am using class components for these, and there are no problems.

Except: the TS definitions will issue a warning about failed prop types:
Warning: Failed prop type: Invalid prop 'TextComponent' of type 'object' supplied to 'HtmlView', expected 'function'.

Can you please update the TS definitions to fix this?