Add CurrentSpeed to GetTransportInfo

This commit adds the CurrentSpeed field to the GetTransportInfo action, including updates to the action definition, handler, and web renderer. The speed is set to '1' as a default value.

pmomediarenderer/src/avtransport/actions/gettransportinfo.rs

@@ -1,4 +1,6 @@
-use crate::avtransport::variables::{A_ARG_TYPE_INSTANCE_ID, TRANSPORTSTATE, TRANSPORTSTATUS};
+use crate::avtransport::variables::{
+    A_ARG_TYPE_INSTANCE_ID, TRANSPORTPLAYSPEED, TRANSPORTSTATE, TRANSPORTSTATUS,
+};
 use pmoupnp::define_action;
 
 define_action! {
@@ -6,5 +8,6 @@ define_action! {
         in "InstanceID" => A_ARG_TYPE_INSTANCE_ID,
         out "CurrentTransportState" => TRANSPORTSTATE,
         out "CurrentTransportStatus" => TRANSPORTSTATUS,
+        out "CurrentSpeed" => TRANSPORTPLAYSPEED,
     }
 }