Improve: multi-line keyword input in notification settings

Replace the single-line, semicolon-separated keyword field with a taller
multi-line edit box (with a vertical scrollbar) where each keyword goes on
its own line. The stored format stays semicolon-separated, so existing
notify.ini files remain valid; load/save convert between newlines and
semicolons, trimming each keyword and skipping empty lines.

Also decode the stored matchPattern as UTF-8 when loading the dialog, so
non-ASCII keywords round-trip correctly (matching the CP_UTF8 encoding
used on save).

Co-Authored-By: deepseek-v4-pro

server/2015Remote/lang/en_US.ini

@@ -1493,7 +1493,7 @@ SMTP
 触发条件:=Trigger:
 匹配列:=Match Column:
 关键词:=Keywords:
-(多个关键词用分号分隔，匹配任一项即触发通知)=(Multiple keywords separated by semicolon)
+(每行一个关键词，匹配任一项即触发通知)=(One keyword per line)
 提示: 同一主机 60 分钟内仅通知一次=Tip: Same host notified only once per 60 minutes
 主机上线=Host Online
 IP地址=IP Address