fix(attributes): text-wrap takes external CSS into account

[kumilingus]

Description

The text-wrap attribute takes external CSS and inherited styles into account when computing the line breaks (previously only explicit inline attributes were considered).

The text-wrap worked properly only when the font attributes were set explicitly.

<text font-size="12">A text to wrap</text>

This PR adds support for external CSS:

<style>
  text { font-size: 12px; }
</style>

...

<text>A text to wrap</text>

Note: Thanks to #2459, all font attributes are evaluated and set before text-wrap, so it is safe to use the getComputedStyle() method.

Fixes #2295.