feat: support third party orm to interact with go-zero (#1286)

* fixes #987

* chore: fix test failure

* chore: add comments

* feat: support third party orm to interact with go-zero

* chore: refactor

zrpc/resolver/internal/subset.go

@@ -0,0 +1,14 @@
+package internal
+
+import "math/rand"
+
+func subset(set []string, sub int) []string {
+	rand.Shuffle(len(set), func(i, j int) {
+		set[i], set[j] = set[j], set[i]
+	})
+	if len(set) <= sub {
+		return set
+	}
+
+	return set[:sub]
+}