fix: support recursive response DTOs and release v0.28.2

examples/recursiveResponse/service.api

@@ -0,0 +1,33 @@
+type Node {
+    Name string `json:"name" binding:"min=1"`
+    Children []Node `json:"children" binding:"max=100"`
+    Next *Node `json:"next,omitempty"`
+    Lookup map[string]Node `json:"lookup,omitempty"`
+}
+
+type Branch {
+    Leaf *Leaf `json:"leaf"`
+}
+
+type Leaf {
+    Branch *Branch `json:"branch"`
+}
+
+@server (group: trees)
+service recursive-example {
+    @handler tree
+    get /tree returns (Node)
+
+    @handler forest
+    get /forest returns ([]Node)
+
+    @handler optional
+    get /optional returns (*Node)
+
+    @handler raw
+    @response raw
+    get /raw returns (Node)
+
+    @handler pair
+    get /pair returns (Branch)
+}