Rename scrcpy threads

Prefix the name of threads by "scrcpy-". This improves readability in
the output of `top -H` for example.

Limit the thread names to 16 bytes, because it is limited on some
platforms.

app/src/receiver.c

@@ -111,8 +111,8 @@ bool
 receiver_start(struct receiver *receiver) {
     LOGD("Starting receiver thread");
 
-    bool ok = sc_thread_create(&receiver->thread, run_receiver, "receiver",
-                               receiver);
+    bool ok = sc_thread_create(&receiver->thread, run_receiver,
+                               "scrcpy-receiver", receiver);
     if (!ok) {
         LOGC("Could not start receiver thread");
         return false;