Feature: #88147 - Add possibility to configure the path to sitemap xslFile

See forge#88147

Description

The xsl file to create a layout for a XML sitemap can now be configured on three levels:

  1. for all sitemaps:

    plugin.tx_seo.config.xslFile = EXT:myext/Resources/Public/CSS/mySite.xsl
    
  2. for all sitemaps of a certain sitemapType:

    plugin.tx_seo.config.<sitemapType>.sitemaps.xslFile = EXT:myext/Resources/Public/CSS/mySite.xsl
    
  3. for a specific sitemap:

    plugin.tx_seo.config.<sitemapType>.sitemaps.<sitemap>.config.xslFile = EXT:myext/Resources/Public/CSS/mySite.xsl
    

Impact

The value is inherited until it is overwritten.

If no value is specified at all, EXT:seo/Resources/Public/CSS/Sitemap.xsl is used as default like before.