feat: support sub-rule, eg.

rules:
  - SUB-RULE,(AND,((NETWORK,TCP),(DOMAIN-KEYWORD,google))),TEST2
  - SUB-RULE,(GEOIP,!CN),TEST1
  - MATCH,DIRECT

sub-rules:
  TEST2:
    - MATCH,Proxy
  TEST1:
    - RULE-SET,Local,DIRECT,no-resolve
    - GEOSITE,CN,Domestic
    - GEOIP,CN,Domestic
    - MATCH,Proxy

tunnel/tunnel.go

@@ -410,8 +410,8 @@ func match(metadata *C.Metadata) (C.Proxy, C.Rule, error) {
 			}
 		}
 
-		if rule.Match(metadata) {
-			adapter, ok := proxies[rule.Adapter()]
+		if matched, ada := rule.Match(metadata); matched {
+			adapter, ok := proxies[ada]
 			if !ok {
 				continue
 			}