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>

ntpdb/querier.go

@@ -6,11 +6,10 @@ package ntpdb
 
 import (
 	"context"
-	"database/sql"
 )
 
 type Querier interface {
-	GetMonitorByName(ctx context.Context, tlsName sql.NullString) (Monitor, error)
+	GetMonitorByNameAndIPVersion(ctx context.Context, arg GetMonitorByNameAndIPVersionParams) (Monitor, error)
 	GetMonitorsByID(ctx context.Context, monitorids []uint32) ([]Monitor, error)
 	GetServerByID(ctx context.Context, id uint32) (Server, error)
 	GetServerByIP(ctx context.Context, ip string) (Server, error)