[feature] Chrome screenshot should only contain the targetted filter part

[dgtlmoon]

When there is a screenshot available, it should only show the element that it is filtered by

[opicron]

I found that puppeteer has a function to make a screen shot of an element only. I think this additional functionality is awesome but I do think that both the full screenshot and filtered element should be captured.

https://github.com/puppeteer/puppeteer/blob/v1.10.0/docs/api.md#elementhandlescreenshotoptions

elementHandle.screenshot([options])

-- options: Same options as in [page.screenshot]

returns: Promise which resolves to buffer with captured screenshot. This method scrolls element into view if needed, and then uses [page.screenshot] to take a screenshot of the element. If the element is detached from DOM, the method throws an error.