Add styles for the "Media & Text" Gutenberg Block

[kjellr]

Coming with Gutenberg 4.1

Will need editor + front end styles. I think we have most of these styles can be borrowed from other blocks (The basic style would be sort of like combining a solid color pullquote block + image block).

[kjellr]

I'm going to close this one for now. Upon testing the block, the default styles are all based on what we have in place already. Through block options like custom color adjustments you can actually achieve most of what you'd need to do, and I think imposing a custom default state would just be confusing.