WFS: Added option PrebindNamespace to WFS configuration

By default, XML namespaces in GetFeature responses are bound when they are needed. This will result in valid output, but may lead to the same namespace being bound again and again in different parts of the response document. Using this new option, namespaces can be bound in the root element, so they are defined for the full scope of the response document and do not need re-definition at several positions in the document.

Example WFS config that makes use of the new option:

```xml
<deegreeWFS configVersion="3.4.0"
  xmlns="http://www.deegree.org/services/wfs"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.deegree.org/services/wfs
  http://schemas.deegree.org/services/wfs/3.4.0/wfs_configuration.xsd">

  <SupportedVersions>
    <Version>2.0.0</Version>
    <Version>1.1.0</Version>
  </SupportedVersions>

  <FeatureStoreId>inspire-ad</FeatureStoreId>

  <EnableTransactions idGen="UseExisting">true</EnableTransactions>
  <EnableResponseBuffering>false</EnableResponseBuffering>

  <QueryCRS>urn:ogc:def:crs:EPSG::4258</QueryCRS>
  <QueryCRS>urn:ogc:def:crs:EPSG::4326</QueryCRS>
  <QueryMaxFeatures>-1</QueryMaxFeatures>
  <QueryCheckAreaOfUse>false</QueryCheckAreaOfUse>

  <GMLFormat gmlVersion="GML_32">
    <MimeType>application/gml+xml; version=3.2</MimeType>
    <MimeType>text/xml; subtype=gml/3.2.1</MimeType>
    <GenerateBoundedByForFeatures>false</GenerateBoundedByForFeatures>
    <GetFeatureResponse xmlns:gml="http://www.opengis.net/gml/3.2">
      <ContainerElement>gml:FeatureCollection</ContainerElement>
      <FeatureMemberElement>gml:featureMember</FeatureMemberElement>
      <AdditionalSchemaLocation>http://www.opengis.net/gml/3.2 http://schemas.opengis.net/gml/3.2.1/deprecatedTypes.xsd
      </AdditionalSchemaLocation>
      <DisableStreaming>false</DisableStreaming>
      <PrebindNamespace prefix="ad" uri="urn:x-inspire:specification:gmlas:Addresses:3.0"/>
      <PrebindNamespace prefix="base" uri="urn:x-inspire:specification:gmlas:BaseTypes:3.2"/>
      <PrebindNamespace prefix="xlink" uri="http://www.w3.org/1999/xlink"/>      
    </GetFeatureResponse>
  </GMLFormat>

</deegreeWFS>
```