Fix #3508 Missing Namespace in Templates

src/Mod/Drawing/Templates/A0_Landscape_plain.svg

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+    xmlns:freecad="http://www.freecadweb.org/wiki/index.php?title=Svg_Namespace"
 	width="1189mm"
 	height="841mm"
 	viewBox="0 0 1189 841">

src/Mod/Drawing/Templates/A0_Portrait_plain.svg

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+    xmlns:freecad="http://www.freecadweb.org/wiki/index.php?title=Svg_Namespace"
 	width="841mm"
 	height="1189mm"
 	viewBox="0 0 841 1189">

src/Mod/Drawing/Templates/A1_Landscape_plain.svg

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+    xmlns:freecad="http://www.freecadweb.org/wiki/index.php?title=Svg_Namespace"
 	width="841mm"
 	height="594mm"
 	viewBox="0 0 841 594">

src/Mod/Drawing/Templates/A1_Portrait_plain.svg

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+    xmlns:freecad="http://www.freecadweb.org/wiki/index.php?title=Svg_Namespace"
 	width="594mm"
 	height="841mm"
 	viewBox="0 0 594 841">

src/Mod/Drawing/Templates/A2_Landscape_plain.svg

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+    xmlns:freecad="http://www.freecadweb.org/wiki/index.php?title=Svg_Namespace"
 	width="594mm"
 	height="420mm"
 	viewBox="0 0 594 420">

src/Mod/Drawing/Templates/A2_Portrait_plain.svg

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+    xmlns:freecad="http://www.freecadweb.org/wiki/index.php?title=Svg_Namespace"
 	width="420mm"
 	height="594mm"
 	viewBox="0 0 420 594">

src/Mod/Drawing/Templates/A3_Landscape_plain.svg

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+    xmlns:freecad="http://www.freecadweb.org/wiki/index.php?title=Svg_Namespace"
 	width="420mm"
 	height="297mm"
 	viewBox="0 0 420 297">

src/Mod/Drawing/Templates/A3_Portrait_plain.svg

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+    xmlns:freecad="http://www.freecadweb.org/wiki/index.php?title=Svg_Namespace"
 	width="297mm"
 	height="420mm"
 	viewBox="0 0 297 420">

src/Mod/Drawing/Templates/A4_Landscape_plain.svg

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+    xmlns:freecad="http://www.freecadweb.org/wiki/index.php?title=Svg_Namespace"
 	width="297mm"
 	height="210mm"
 	viewBox="0 0 297 210">

src/Mod/Drawing/Templates/A4_Portrait_plain.svg

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1"
+    xmlns:freecad="http://www.freecadweb.org/wiki/index.php?title=Svg_Namespace"
 	width="210mm"
 	height="297mm"
 	viewBox="0 0 210 297">