[oneDPL] oneDPL '__future' class code cleanup and API fix #116

Job	Run time
HOST,bknd=tbb,cmplr=icx-cl,windows-latest,std=c++17,cfg=release	18m 17s
CPU,bknd=dpcpp,cmplr=icpx,ubuntu-latest,std=с++17,cfg=release	15m 17s
HOST,bknd=tbb,cmplr=cl,windows-latest,std=c++17,cfg=release	16m 10s
FPGA_EMU,bknd=dpcpp,cmplr=icpx,ubuntu-latest,std=с++17,cfg=release	23m 55s
clang-format	12s
CPU,bknd=dpcpp,cmplr=icx,windows-latest,std=c++17,cfg=release	10m 58s
HOST,bknd=omp,cmplr=clang++,macos-latest,std=c++17,cfg=release	4m 39s
HOST,bknd=tbb,cmplr=icpx,ubuntu-latest,std=с++17,cfg=release	11m 50s
HOST,bknd=omp,cmplr=icpx,ubuntu-latest,std=с++17,cfg=release	9m 42s
HOST,bknd=omp,cmplr=g++,ubuntu-latest,std=с++17,cfg=release	5m 57s
HOST,bknd=tbb,cmplr=g++,ubuntu-latest,std=с++17,cfg=release	8m 50s
HOST,bknd=tbb,cmplr=g++,ubuntu-latest,std=с++17,cfg=release	8m 49s
HOST,bknd=tbb,cmplr=clang++,ubuntu-latest,std=с++17,cfg=release	11m 4s
HOST,bknd=omp,cmplr=clang++,ubuntu-latest,std=с++17,cfg=release	8m 45s
HOST,bknd=tbb,cmplr=clang++,ubuntu-latest,std=с++17,cfg=release	10m 49s
HOST,bknd=tbb,cmplr=icpx,ubuntu-latest,std=с++17,cfg=release	11m 34s
HOST,bknd=serial,cmplr=g++,ubuntu-latest,std=с++17,cfg=release	4m 59s
CPU,bknd=dpcpp,cmplr=icpx,ubuntu-latest,std=с++20,cfg=release	26m 25s
HOST,bknd=tbb,cmplr=icpx,ubuntu-latest,std=с++20,cfg=release	17m 34s
HOST,bknd=omp,cmplr=icpx,ubuntu-latest,std=с++20,cfg=release	18m 7s
	4h 3m 53s

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