performance benchmarks: Aggregate and report CPU frame times. (#2939)

* Add CaptureCpuFrameTime method to ProfilingCaptureSystemComponent for monitoring CPU performance.

Signed-off-by: Cynthia Lin <cyntlin@amazon.com>

* ly_test_tools: Refactor benchmark data aggregator in preparation for CPU frame times.

Signed-off-by: Cynthia Lin <cyntlin@amazon.com>

* performance benchmarks: Aggregate and report CPU frame times based on JSON data.

Signed-off-by: Cynthia Lin <cyntlin@amazon.com>

* AutomatedTesting: Capture CPU frame time in AtomFeatureIntegrationBenchmark.

Signed-off-by: Cynthia Lin <cyntlin@amazon.com>

AutomatedTesting/Gem/PythonTests/atom_renderer/test_Atom_GPUTests.py

@@ -99,6 +99,7 @@ class TestPerformanceBenchmarkSuite(object):
         expected_lines = [
             "Benchmark metadata captured.",
             "Pass timestamps captured.",
+            "CPU frame time captured.",
             "Capturing complete.",
             "Captured data successfully."
         ]
@@ -106,6 +107,7 @@ class TestPerformanceBenchmarkSuite(object):
         unexpected_lines = [
             "Failed to capture data.",
             "Failed to capture pass timestamps.",
+            "Failed to capture CPU frame time.",
             "Failed to capture benchmark metadata."
         ]