Add option to not power on on start

By default, on start, the device is powered on. To prevent this
behavior, add a new option --no-power-on.

Fixes #3148 <https://github.com/Genymobile/scrcpy/issues/3148>
PR #3210 <https://github.com/Genymobile/scrcpy/pull/3210>

app/src/server.c

@@ -248,6 +248,10 @@ execute_server(struct sc_server *server,
         // By default, cleanup is true
         ADD_PARAM("cleanup=false");
     }
+    if (!params->power_on) {
+        // By default, power_on is true
+        ADD_PARAM("power_on=false");
+    }
 
 #undef ADD_PARAM