fix(api): protocol-aware monitor filtering for multi-protocol monitors

Servers with monitor filtering returned incorrect results when monitors
have same names but different protocols (v4/v6). Monitor lookup now
considers both name and IP version to match the correct protocol.

- Add GetMonitorByNameAndIPVersion SQL query with protocol matching
- Update history parameter parsing to use server IP version context
- Fix both /scores/{ip}/log and Grafana endpoints
- Remove unused GetMonitorByName query

Fixes abh/ntppool#264
Reported-by: Anssi Johansson <https://github.com/avijc>

query.sql

@@ -47,10 +47,13 @@ select * from servers
 where
   ip = sqlc.arg(ip);
 
--- name: GetMonitorByName :one
+-- name: GetMonitorByNameAndIPVersion :one
 select * from monitors
 where
-  tls_name like sqlc.arg('tls_name')
+  tls_name like sqlc.arg('tls_name') AND
+  ip_version = sqlc.arg('ip_version') AND
+  is_current = 1 AND
+  status != 'deleted'
   order by id
   limit 1;