fix: add missing space between digit groups in comma-separated numbers (#291)

Numbers like 0,013,225 were normalized to "oh zero one threetwo two
five" with "three" and "two" concatenated. The comma-separated digit
groups in single_digits_graph_with_commas lacked a space separator
between groups.

Author: pengzhendong

tn/english/rules/cardinal.py

@@ -72,7 +72,13 @@ def build_tagger(self):
                     + single_digits_graph
                     + self.INSERT_SPACE
                     + single_digits_graph
-                ).plus
+                    + (self.INSERT_SPACE + pynutil.delete(",")
+                       + single_digits_graph
+                       + self.INSERT_SPACE
+                       + single_digits_graph
+                       + self.INSERT_SPACE
+                       + single_digits_graph).star
+                )
             )
 
         graph = (