Dara: Update editor styles

[scruffian]

Changes proposed in this Pull Request:

This updates Dara to use the main style sheets as editor styles with exceptions for the title and content background.

Related issue(s):

Part of #3280

[pbking]

I appears that due to this recent Gutenberg change that default Button Block styles now receive a black border by default (though, in the view only, not the editor... which seems EXTRA strange).

Issue opened to address that opened here.

[pbking]

There appear to be alignment discrepancies between the view and the editor. I don't believe this is due to this change as it's the view that appears to be incorrect. Just noting it...

Editor:

View:

[pbking]

The editor appears to have lost the padding in the Cover Block.

Editor Before:

Editor After:

View:

Note that the cover block is pink in the view and black in the editor, but this is something that existed before the change.