Fix nick character counting: Add missing underscore and pipe chars

- Add missing '_' (underscore) and '|' (pipe) to count_nick_chars()
- Now matches isnickchar definition from fe-messages.c
- Fixes issue where nicks like 'big_Fat_boy' weren't truncated properly
- Nick counting now includes: alphanumeric + `-_[]{}|\^

Test case: 'big_Fat_boy' (11 chars) should now be truncated to 'big_Fat_b>>'
with width=10

Timestamp: 2025-01-25 00:08

config_dev

@@ -319,7 +319,7 @@ settings = {
     theme = "default.theme";
     nick_column_enabled = "yes";
     nick_column_width = "10";
-    debug_nick_column = "yes";
+    debug_nick_column = "no";
   };
   "fe-text" = {
     lag_min_show = "1s";