rename olp/porting/optional.hpp into optional.h #2020

Job	Run time
PSV.Linux.22.04.gcc9.Cpplint	8m 45s
PSV.Linux.22.04.gcc9.Tests.CodeCov	10m 21s
PSV.Linux.22.04.gcc9.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	2m 36s
PSV.Linux.22.04.gcc13	8m 30s
PSV.MacOS14.Xcode15	3m 31s
PSV.iOS.MacOS13.Xcode15	11m 15s
PSV.Linux.latest.gcc14.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	3m 2s
PSV.Linux.22.04.clang	8m 56s
PSV.MacOS13.Xcode15.x86_64	5m 38s
PSV.Linux.22.04.gcc11.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	2m 30s
PSV.Linux.22.04.gcc11	8m 7s
PSV.MacOS15.Xcode16	4m 5s
PSV.Linux.Android.22.04	5m 17s
PSV.iOS.MacOS13.Xcode14	9m 12s
PSV.iOS.MacOS14.Xcode15	5m 21s
PSV.iOS.MacOS15.Xcode16	11m 11s
PSV.Win.VC2022	9m 34s
PSV.Clang.Format.Checker	29s
PSV.Commit.Checker	5s
	1h 58m 25s

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