add support for target.overrideTo in dial verb

lib/tasks/specs.json

@@ -292,7 +292,8 @@
       "sipUri": "string",
       "auth": "#auth",
       "vmail": "boolean",
-      "tenant": "string"
+      "tenant": "string",
+      "overrideTo": "string"
     },
     "required": [
       "type"

lib/utils/place-outdial.js

@@ -59,6 +59,7 @@ class SingleDialer extends Emitter {
 
   async exec(srf, ms, opts) {
     opts = opts || {};
+    opts.headers = opts.headers || {};
     let uri, to;
     try {
       switch (this.target.type) {
@@ -69,7 +70,6 @@ class SingleDialer extends Emitter {
           to = this.target.number;
           if ('teams' === this.target.type) {
             assert(this.target.teamsInfo);
-            opts.headers = opts.headers || {};
             Object.assign(opts.headers, {
               'X-MS-Teams-FQDN': this.target.teamsInfo.ms_teams_fqdn,
               'X-MS-Teams-Tenant-FQDN': this.target.teamsInfo.tenant_fqdn
@@ -83,6 +83,12 @@ class SingleDialer extends Emitter {
           uri = `sip:${this.target.name}`;
           to = this.target.name;
 
+          if (this.target.overrideTo) {
+            Object.assign(opts.headers, {
+              'X-Override-To': this.target.overrideTo
+            });
+          }
+
           // need to send to the SBC registered on
           const reg = await registrar.query(aor);
           if (reg) {