Add definitions for aws-iot-device-sdk (DefinitelyTyped#12556)

* Add definitions for aws-iot-device-sdk

This adds initial (but fully covering) definitions for aws-iot-device-sdk.

* Add version tag

* Rename test file to match spec exactly

* Fix typo from old test file name

* Remove top level module statement

As per DefinitelyTyped#12556 (comment)

* Remove redundant definition import

* Use unions instead of multiple overloads

* Clarify callback type

* Update param jsdoc from mqtt source

* Remove redundant reference imports

aws-iot-device-sdk/aws-iot-device-sdk-tests.ts

@@ -0,0 +1,103 @@
+// Code adapted from
+// https://github.com/aws/aws-iot-device-sdk-js/blob/97b0b468d59e02e2f6a1dce321000d914cb47894/examples/device-example.js
+// and
+// https://github.com/aws/aws-iot-device-sdk-js/blob/97b0b468d59e02e2f6a1dce321000d914cb47894/examples/thing-example.js
+
+import * as awsIot from "aws-iot-device-sdk";
+import * as mqtt from "mqtt";
+
+const device = new awsIot.device({
+  keyPath: "",
+  certPath: "",
+  caPath: "",
+  clientId: "",
+  region: "",
+  baseReconnectTimeMs: 1000,
+  keepalive: 10,
+  protocol: "wss",
+  port: 443,
+  host: "",
+  debug: false
+});
+
+device.subscribe("topic_1");
+
+device
+      .on("connect", function() {
+         console.log("connect");
+      });
+   device
+      .on("close", function() {
+         console.log("close");
+      });
+   device
+      .on("reconnect", function() {
+         console.log("reconnect");
+      });
+   device
+      .on("offline", function() {
+         console.log("offline");
+      });
+   device
+      .on("error", function(error) {
+         console.log("error", error);
+      });
+   device
+      .on("message", function(topic: string, payload: any) {
+         console.log("message", topic, payload.toString());
+      });
+
+
+const thingShadows = new awsIot.thingShadow({
+    keyPath: "",
+    certPath: "",
+    caPath: "",
+    clientId: "",
+    region: "",
+    baseReconnectTimeMs: 1000,
+    keepalive: 10,
+    protocol: "mqtts",
+    port: 0,
+    host: "",
+    debug: false
+ });
+
+ thingShadows.register(
+   "thingName",
+   { ignoreDeltas: false },
+   (err: Error, failedTopics: mqtt.Granted[]) => { }
+ );
+
+ thingShadows.on("connect", function() {
+     console.log("connected to AWS IoT");
+  });
+
+  thingShadows.on("close", function() {
+     console.log("close");
+     thingShadows.unregister("thingName");
+  });
+
+  thingShadows.on("reconnect", function() {
+     console.log("reconnect");
+  });
+
+  thingShadows.on("offline", function() {
+     console.log("offline");
+  });
+
+  thingShadows.on("error", function(error) {
+     console.log("error", error);
+  });
+
+  thingShadows.on("message", function(topic: string, payload: any) {
+     console.log("message", topic, payload.toString());
+  });
+
+  thingShadows.on("status", function(thingName: string, stat: "accepted" | "rejected", clientToken: string, stateObject: any) {
+  });
+
+  thingShadows.on("delta", function(thingName, stateObject) {
+  });
+
+  thingShadows.on("timeout", function(thingName, clientToken) {
+  });