Add classes for Task and SharedTask in threadpool #7537

Job	Run time
ci2 / ubuntu-20.04 - GCS	1m 56s
ci1 / ubuntu-22.04 - AZURE	1m 41s
ci4 / macos-latest - S3	5m 0s
ci3 / ubuntu-22.04 - SERIALIZATION	1m 31s
ci5 / macos-latest - GCS	1s
ci6 / ubuntu-22.04 - Experimental	1m 45s
ci7 / ubuntu-22.04 - S3	3m 42s
ci8 / ubuntu-20.04 - ASAN	6m 10s
ci9 / macos-latest - AZURE	1s
backward_compatibility / Build tiledb_unit (ubuntu-20.04)	4m 40s
ci_docker / build-dockerfile	6m 9s
ci_manylinux / ubuntu-20.04 - MANYLINUX	29s
ci_mingw_r / build (ucrt64, ucrt-x86_64)	6m 0s
ci_msvc / windows-2019 - azure	5m 55s
standalone / Build - macos-latest	1s
ci_msvc / windows-2019 - s3	5m 56s
standalone / Build - ubuntu-latest	6m 9s
ci_msvc / windows-2019 - gcs	5m 56s
standalone / Build - windows-latest	5m 52s
ci_msvc / windows-2019 - serialization	5m 55s
ci_msvc / windows-2022 - azure	5m 51s
ci_msvc / windows-2022 - s3	5m 53s
ci_msvc / windows-2022 - gcs	5m 54s
ci_msvc / windows-2022 - serialization	5m 53s
backward_compatibility / ${{ matrix.tiledb_version }}	0s
full_ci_passed	1s
	1h 38m 21s

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