Text symbolizer resets color to #000000

[rdewit]

Bug

Describe the bug
The SLD parser appears to not parse the text color properly and resets it to #000000. This happens with SLDs from QGIS as well as the SLD generated by the demo app.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://geostyler.github.io/geostyler-demo/
2. Edit Rule 1 to be of Kind: Text and choose a color other than black
3. Copy the SLD in the Code Editor to clipboard
4. Reload the page and paste the SLD from clipboard
5. Observe that the CSS parameter fill in Fill changes from your chosen color to #000000

Expected behavior
The SLD parser should recognize the the color and not change it to the default.

Additional context
I had a quick glance through the code of the SLD parser and I couldn't immediately see what is going wrong as it tries to extract the fill and fill-opacity from the CSS parameters.

[jansule]

Thanks for the info @rdewit.

@KaiVolland fixed this in #532