Add GET_CLIPBOARD device event

Add the first device event, used to forward the device clipboard to the
computer.

server/src/main/java/com/genymobile/scrcpy/DeviceEvent.java

@@ -0,0 +1,27 @@
+package com.genymobile.scrcpy;
+
+public final class DeviceEvent {
+
+    public static final int TYPE_GET_CLIPBOARD = 0;
+
+    private int type;
+    private String text;
+
+    private DeviceEvent() {
+    }
+
+    public static DeviceEvent createGetClipboardEvent(String text) {
+        DeviceEvent event = new DeviceEvent();
+        event.type = TYPE_GET_CLIPBOARD;
+        event.text = text;
+        return event;
+    }
+
+    public int getType() {
+        return type;
+    }
+
+    public String getText() {
+        return text;
+    }
+}