Fixed issue with <kombi_request/> not using utf-8

[rimi-itk]

Sometimes (!) https://digitaliseringskataloget.dk/integration/sf1601 has trouble understanding numeric XML entities, e.g.

        <memo:label>G&#xE5; til samtykke</memo:label>

which leads to random errors depending on a lot of factors.

It seems that the issue stems from the kombi_request document not using the utf-8 encoding. We could fix this by changing

    <xsl:output method="xml"/>

to

    <xsl:output method="xml" encoding="utf-8"/>

in src/Service/SF1601/resources/namespaces.xslt, but it seems that we don't need that weird namespace transformation anymore, i.e. we can just use the XML document as it is.