Allow number filtering on Dispatch Rules (#707)

Allow inbound number filtering on  SIP Dispatch Rules. It works similar to Trunks, where rules without a number filter are grouped together and take less priority than number-specific rules.

While at it, simplify the rule evaluation.

Previously it was doing some hand-crafted checks for evaluation path, that matched the validation path. Same double logic existed for priorities as well.

Now the validation is always called from evaluation, thus sharing the logic. And rule selection is simplified by just picking the first one after priority filtering.

Author: dennwc

.changeset/nervous-dolphins-nail.md

@@ -0,0 +1,6 @@
+---
+"github.com/livekit/protocol": minor
+"@livekit/protocol": minor
+---
+
+Allow inbound number filtering on SIP Dispatch Rules

livekit/livekit_sip.pb.go

@@ -173,23 +173,32 @@ message CreateSIPDispatchRuleRequest {
   // If true a random value will be used instead
   bool hide_phone_number = 3;
 
+  // Dispatch Rule will only accept a call made to these numbers (if set).
+  repeated string inbound_numbers = 6;
+
   // Optional human-readable name for the Dispatch Rule.
   string name = 4;
   // Optional user-defined metadata for the Dispatch Rule.
   string metadata = 5;
+
+  // NEXT ID: 7
 }
 
 message SIPDispatchRuleInfo {
   string sip_dispatch_rule_id = 1;
   SIPDispatchRule rule = 2;
   repeated string trunk_ids = 3;
   bool hide_phone_number = 4;
+  // Dispatch Rule will only accept a call made to these numbers (if set).
+  repeated string inbound_numbers = 7;
 
   // Human-readable name for the Dispatch Rule.
   string name = 5;
   // User-defined metadata for the Dispatch Rule.
   // Participants created by this rule will inherit this metadata.
   string metadata = 6;
+
+  // NEXT ID: 8
 }
 
 message ListSIPDispatchRuleRequest {