[DEV-13308] list2typedef automatically sets first item as _NONE with 0 value

This was done so we can use t:param template with the generated
enum, but not have to provide the value in the YML test. Without
a NONE enum as 0, the default value of 0 in YML test will have
a domain violation.

build-aux/list2typedef

@@ -155,6 +155,7 @@ main()
          title="$typedef Type">
   <typedef name="$typedef" desc="$typedef">
     <enum type="integer">
+      <item name="${typedef^^}_NONE" value="0" desc="NONE" />
 EOF
 
   while read line; do

build-aux/test/test-list2typedef

@@ -43,6 +43,7 @@ Second'\''s @     @Line
          title="FooType Type">
   <typedef name="FooType" desc="FooType">
     <enum type="integer">
+      <item name="FOOTYPE_NONE" value="0" desc="NONE" />
       <item name="FOOTYPE_FIRST" value="2706493105" desc="First" />
       <item name="FOOTYPE_SECONDS_LINE" value="3512333918" desc="Second'\''s @     @Line" />
       <item name="FOOTYPE_THIRD" value="519392729" desc="!!!THIRD!!!" />