Add mdns (#2054)

* improve grpc tests

* add mdns

packages/m/mdns/xmake.lua

@@ -0,0 +1,23 @@
+package("mdns")
+    set_kind("library", {headeronly = true})
+    set_homepage("https://github.com/mjansson/mdns")
+    set_description("Public domain mDNS/DNS-SD library in C")
+
+    add_urls("https://github.com/mjansson/mdns/archive/refs/tags/$(version).tar.gz",
+             "https://github.com/mjansson/mdns.git")
+    add_versions("1.4.2", "c69cfdebe28a489c85f33744f7811c40572a9769a81cd57ecc09ef95802347f2")
+
+    add_deps("cmake")
+
+    if is_plat("windows", "mingw") then
+        add_syslinks("iphlpapi", "ws2_32")
+    end
+
+    on_install(function (package)
+        local configs = {"-DMDNS_BUILD_EXAMPLE=OFF"}
+        import("package.tools.cmake").install(package, configs)
+    end)
+
+    on_test(function (package)
+        assert(package:has_cfuncs("mdns_query_answer_multicast", {includes = "mdns.h"}))
+    end)