[YAML] Make busyWait a dedicated method instead of always generating …

…it (#15416)

* [YAML] Make busyWait a dedicated method instead of always generating it

* Update generated tests content

examples/chip-tool/templates/tests/partials/test_cluster.zapt

@@ -288,13 +288,8 @@ class {{filename}}: public TestCommand
 
         {{~#*inline "maybeWait"}}
           {{#if busyWaitMs}}
-          {
-            using namespace chip::System::Clock::Literals;
-            // Busy-wait for {{busyWaitMs}} milliseconds.
-            auto & clock = chip::System::SystemClock();
-            auto start = clock.GetMonotonicTimestamp();
-            while (clock.GetMonotonicTimestamp() - start < {{busyWaitMs}}_ms);
-          }
+          using namespace chip::System::Clock::Literals;
+          BusyWaitFor({{busyWaitMs}}_ms);
           {{/if}}
         {{/inline~}}
 

src/app/tests/suites/commands/delay/DelayCommands.cpp

@@ -63,3 +63,14 @@ CHIP_ERROR DelayCommands::RunInternal(const char * command)
     VerifyOrReturnError(system(command) == 0, CHIP_ERROR_INTERNAL);
     return ContinueOnChipMainThread(CHIP_NO_ERROR);
 }
+
+CHIP_ERROR DelayCommands::BusyWaitFor(chip::System::Clock::Milliseconds32 durationInMs)
+{
+    auto & clock = chip::System::SystemClock();
+    auto start   = clock.GetMonotonicTimestamp();
+    while (clock.GetMonotonicTimestamp() - start < durationInMs)
+    {
+        // nothing to do.
+    };
+    return CHIP_NO_ERROR;
+}

src/app/tests/suites/commands/delay/DelayCommands.h

@@ -37,6 +37,9 @@ class DelayCommands
     CHIP_ERROR WaitForCommissionableAdvertisement();
     CHIP_ERROR WaitForOperationalAdvertisement();
 
+    // Busy-wait for a given duration in milliseconds
+    CHIP_ERROR BusyWaitFor(chip::System::Clock::Milliseconds32 durationInMs);
+
 private:
     static void OnWaitForMsFn(chip::System::Layer * systemLayer, void * context);
     CHIP_ERROR RunInternal(const char * command);