Add query2 numeric comparison operators

These were recently added to the python version.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

htools/Ganeti/Query2.hs

@@ -101,6 +101,10 @@ data Filter
     | NotFilter Filter -- ^ ! <expression>
     | TrueFilter FilterField -- ^ ? <field>
     | EqualFilter FilterField FilterValue -- ^ (=|!=) <field> <value>
+    | LessThanFilter FilterField FilterValue -- ^ < <field> <value>
+    | GreaterThanFilter FilterField FilterValue -- ^ > <field> <value>
+    | LEThanFilter FilterField FilterValue -- ^ <= <field> <value>
+    | GEThanFilter FilterField FilterValue -- ^ >= <field> <value>
     | RegexpFilter FilterField FilterRegexp -- ^ =~ <field> <regexp>
     | ContainsFilter FilterField FilterValue -- ^ =[] <list-field> <value>