Properly encode direction symbols in style templates (#6812)

NOTE: this commit does NOT fix the project save operation,
      but only an output of that operation

Author: Sandro Santilli

python/plugins/db_manager/db_plugins/postgis/plugins/qgis_topoview/templates/next_left.qml

@@ -77,7 +77,7 @@
     <property key="labeling/isExpression" value="false"/>
     <property key="labeling/labelOffsetInMapUnits" value="true"/>
     <property key="labeling/labelPerPart" value="false"/>
-    <property key="labeling/leftDirectionSymbol" value="< "/>
+    <property key="labeling/leftDirectionSymbol" value="&lt; "/>
     <property key="labeling/mergeLines" value="false"/>
     <property key="labeling/minFeatureSize" value="0"/>
     <property key="labeling/multiLineLabels" value="false"/>
@@ -93,7 +93,7 @@
     <property key="labeling/previewBkgrdColor" value="#ffffff"/>
     <property key="labeling/priority" value="2"/>
     <property key="labeling/reverseDirectionSymbol" value="false"/>
-    <property key="labeling/rightDirectionSymbol" value=" >"/>
+    <property key="labeling/rightDirectionSymbol" value=" &gt;"/>
     <property key="labeling/scaleMax" value="0"/>
     <property key="labeling/scaleMin" value="0"/>
     <property key="labeling/textColorB" value="0"/>

python/plugins/db_manager/db_plugins/postgis/plugins/qgis_topoview/templates/next_right.qml

@@ -77,7 +77,7 @@
     <property key="labeling/isExpression" value="false"/>
     <property key="labeling/labelOffsetInMapUnits" value="true"/>
     <property key="labeling/labelPerPart" value="false"/>
-    <property key="labeling/leftDirectionSymbol" value="< "/>
+    <property key="labeling/leftDirectionSymbol" value="&lt; "/>
     <property key="labeling/mergeLines" value="false"/>
     <property key="labeling/minFeatureSize" value="0"/>
     <property key="labeling/multiLineLabels" value="false"/>
@@ -93,7 +93,7 @@
     <property key="labeling/previewBkgrdColor" value="#ffffff"/>
     <property key="labeling/priority" value="3"/>
     <property key="labeling/reverseDirectionSymbol" value="true"/>
-    <property key="labeling/rightDirectionSymbol" value=" >"/>
+    <property key="labeling/rightDirectionSymbol" value=" &gt;"/>
     <property key="labeling/scaleMax" value="0"/>
     <property key="labeling/scaleMin" value="0"/>
     <property key="labeling/textColorB" value="0"/>