[cli] update borderagent discover to allow network interface selection for mDNS binding

src/app/border_agent_functions_mock.cpp

@@ -43,9 +43,9 @@ void ClearBorderAgentFunctionsMock()
     gBorderAgentFunctionsMock = nullptr;
 }
 
-Error DiscoverBorderAgent(BorderAgentHandler aBorderAgentHandler, size_t aTimeout)
+Error DiscoverBorderAgent(BorderAgentHandler aBorderAgentHandler, size_t aTimeout, const std::string &aNetIf)
 {
-    return gBorderAgentFunctionsMock->DiscoverBorderAgent(aBorderAgentHandler, aTimeout);
+    return gBorderAgentFunctionsMock->DiscoverBorderAgent(aBorderAgentHandler, aTimeout, aNetIf);
 }
 
 } // namespace commissioner

src/app/border_agent_functions_mock.hpp

@@ -45,7 +45,7 @@ class BorderAgentFunctionsMock
 public:
     virtual ~BorderAgentFunctionsMock() = default;
 
-    MOCK_METHOD(Error, DiscoverBorderAgent, (BorderAgentHandler, size_t));
+    MOCK_METHOD(Error, DiscoverBorderAgent, (BorderAgentHandler, size_t, const std::string));
 };
 
 void SetBorderAgentFunctionsMock(ot::commissioner::BorderAgentFunctionsMock *ptr);

src/app/cli/interpreter_test.cpp

@@ -1629,7 +1629,7 @@ TEST_F(InterpreterTestSuite, PC_BorderagentDiscover)
     BorderAgentFunctionsMock bafm;
     SetBorderAgentFunctionsMock(&bafm);
 
-    EXPECT_CALL(bafm, DiscoverBorderAgent(_, _)).WillOnce(Return(Error{}));
+    EXPECT_CALL(bafm, DiscoverBorderAgent(_, _, _)).WillOnce(Return(Error{}));
 
     Interpreter::Expression expr;
     Interpreter::Value      value;