feat: add download, upload and total traffic columns to connections list

[Tarkiin]

This PR adds three traffic columns to the Connections tab for TCP connections (IPv4 and IPv6):

• ↓ Speed: Current download speed, refreshed with the network monitor.
• ↑ Speed: Current upload speed, refreshed with the network monitor.
• Total: Accumulated download + upload bytes since the connection was detected by simplewall.

Technical details

1. Uses GetPerTcpConnectionEStats / SetPerTcpConnectionEStats and their IPv6 equivalents from IP Helper.
2. Fails gracefully when TCP extended statistics are unavailable or cannot be enabled.
3. Uses routine's _r_sys_gettickcount64 and _r_format_bytesize64 helpers.
4. Traffic columns are numerically sortable.
5. Adds IDS_TOTAL to resources, !example.txt, and Spanish.ini.
6. UDP rows remain empty because Windows does not expose equivalent per-connection UDP statistics through this API.

The branch has been rewritten on top of the current master source.

[henrypp]

there is errors:

_r_listview_additem (hwnd, IDC_NETWORK, INT_MAX
adds item with INT_MAX which adds item to nowhere, but INT_ERROR adds to latest item

GetTickCount64
routine already have _r_sys_gettickcount64

[Tarkiin]

Thank you for the review! Both issues have been fixed:

1. INT_ERROR restored — Reverted the listview insertion index back to INT_ERROR as it was originally. Sorry for the unnecessary change.
2. _r_sys_gettickcount64 — Replaced GetTickCount64() with _r_sys_gettickcount64() from routine.
   Both fixes are already pushed to this PR branch.

[henrypp]

now rewrite PR required! bcs a lot of changed in source, i think almost complete code rewritten

[Tarkiin]

Rewritten on top of current master (42f0e61) and force-pushed as ee2a86a.

• Resolved the conflicts in src/listview.c, src/resource.h, and src/resource.rc.
• Kept INT_ERROR for listview insertion.
• Uses _r_sys_gettickcount64 and routine's _r_format_bytesize64.
• Preserved the new resource IDs from current master (IDS_TOTAL is now 280).

GitHub now reports no conflicts with the base branch.