add Pahomqttcpp package (#2765)

* add pahomqttc package

* add Pahomqttcpp package

* fix is_plat + fix cmake build opts

* update xmake.lua

* macos -> macosx + fix lib cmake opt

* var renaming

packages/p/pahomqttcpp/xmake.lua

@@ -0,0 +1,45 @@
+package("pahomqttcpp")
+    set_homepage("https://github.com/eclipse/paho.mqtt.cpp")
+    set_description("Eclipse Paho MQTT C++ Client Library")
+    set_license("EPL v1.0")
+
+    add_urls("https://github.com/eclipse/paho.mqtt.cpp/archive/refs/tags/$(version).zip",
+             "https://github.com/eclipse/paho.mqtt.cpp.git")
+
+    add_versions("v1.2.0", "90c4d8ae4f56bb706120fddcc5937cd0a0360b6f39d5cd5574a5846c0f923473")
+    
+    add_deps("cmake")
+    add_deps("pahomqttc")
+
+    on_install("windows", "linux", "macosx", function (package)
+        
+        local configs = {"-DPAHO_WITH_SSL=FALSE"}
+        table.insert(configs, "-DCMAKE_BUILD_TYPE=" .. (package:debug() and "Debug" or "Release"))
+        table.insert(configs, "-DBUILD_SHARED_LIBS=" .. (package:config("shared") and "ON" or "OFF"))
+
+        if package:is_plat("windows") then
+            local pahomqttc = package:dep("pahomqttc"):fetch()
+
+            local includedirs = pahomqttc.includedirs or pahomqttc.sysincludedirs
+            if includedirs and #includedirs > 0 then
+                table.insert(configs, "-DPAHO_MQTT_C_INCLUDE_DIRS=" .. table.concat(includedirs, " "))
+            end
+
+            local libfiles = pahomqttc.libfiles
+            if libfiles then
+                table.insert(configs, "-DPAHO_MQTT_C_LIBRARIES=" .. table.concat(libfiles, " "))
+            end
+        end
+        
+        import("package.tools.cmake").install(package, configs)
+    end)
+
+    on_test(function (package)
+        assert(package:check_cxxsnippets({test = [[
+            #include <mqtt/client.h>
+            void test() {
+                mqtt::client cli{"localhost", "some_id"};
+                cli.connect();
+            }
+        ]]}, {configs = {languages = "c++11"}}))
+    end)