Fix support for base64 encoded url values in styles

[cupojoe]

Take this example style attribute, it strips the background-image property from the semicolon forward

<span style="padding-bottom: 56.25%; position: relative; bottom: 0; left: 0; background-image: url('data:image/jpeg;base64,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'); background-size: cover; display: block;">

Which then throws errors in the browser:

GET data:image/jpeg net::ERR_INVALID_URL

I believe the issue is here:

hast-to-hyperscript/index.js

Line 213 in 68de5b0

var declarations = value.split(';');

When the styles get separated assuming the separator is a semicolon, which is a valid character in a base64 string.

[cupojoe]

Closing in favor of parsing the style string attribute using a different library before passing it to this one.