Add support for inline svg data source in xml format in CSS

[vasilyevia]

OpenHtmlToPdf lib supports base64 encoded inline svg data source (#485).

It would be great to also have support for inline xml data source in CSS like the following:
.some-class { background-image:url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="9" height="12" viewBox="0 0 9 12"><path fill="#5e6c75" d="M0.722,4.823L-0.01,4.1,4.134-.01,4.866,0.716Zm7.555,0L9.01,4.1,4.866-.01l-0.732.726ZM0.722,7.177L-0.01,7.9,4.134,12.01l0.732-.726Zm7.555,0L9.01,7.9,4.866,12.01l-0.732-.726Z"/></svg>'); }

[maneesh-echo]

.some-class {
background: url('resources/image.svg');
}

this also doesn't work and it gives the following warning
com.openhtmltopdf.load WARNING:: Unrecognized image format for: file

It would be great to also have this support.