feat: add outbound trunk config for create_sip_participant. (#771)

* feat: add outbound trunk config for create_sip_participant.

* fix.

* Update sip.rs

Author: cloudwebrtc

livekit-api/src/services/sip.rs

@@ -417,13 +417,15 @@ impl SIPClient {
         call_to: String,
         room_name: String,
         options: CreateSIPParticipantOptions,
+        outbound_trunk_config: Option<proto::SipOutboundConfig>,
     ) -> ServiceResult<proto::SipParticipantInfo> {
         self.client
             .request(
                 SVC,
                 "CreateSIPParticipant",
                 proto::CreateSipParticipantRequest {
                     sip_trunk_id: sip_trunk_id.to_owned(),
+                    trunk: outbound_trunk_config,
                     sip_call_to: call_to.to_owned(),
                     sip_number: options.sip_number.to_owned().unwrap_or_default(),
                     room_name: room_name.to_owned(),