create_treelog_xml function

Creates the XML text for the logger tag with ID treelog. This section has these elements: <logger id="treelog.t:test_output_0" spec="Logger" fileName="my_treelog.trees" logEvery="345000" mode="tree" sanitiseHeaders="true" sort="smart"> # nolint indeed long <log id="TreeWithMetaDataLogger.t:test_output_0" spec="beast.evolution.tree.TreeWithMetaDataLogger" tree="@Tree.t:test_output_0"/> # nolint indeed long </logger>