[transliteration] Using revisit strings instead of keeping a backtrack count so we don't have to later map logical characters to the actual string, removing any duplicate keys in the table builder so that if any rules happen to overlap within a step, the first will take precedence

src/transliteration_rule.h

@@ -29,7 +29,8 @@ typedef struct transliteration_rule_source {
     char *replacement;
     size_t replacement_len;
 
-    int move;
+    char *revisit;
+    size_t revisit_len;
 
     char *group_regex_str;
     size_t group_regex_len;