Add start() method to the SocketReactor #2775

Job	Run time
android-arm64-v8a-ndk-cmake	8m 24s
android-arm64-v8a-ndk-latest-cmake	7m 45s
android-armeabi-v7a-ndk-cmake	8m 51s
linux-gcc-make-armv7l	14m 8s
linux-gcc-make	21m 57s
linux-gcc-make-asan	27m 20s
linux-gcc-make-asan-no-soo	27m 4s
linux-gcc-make-cxx20	27m 6s
linux-gcc-make-trace	22m 33s
linux-gcc-make-tsan	22m 42s
linux-gcc-make-ubsan	31m 55s
linux-emscripten-cmake	4m 43s
linux-gcc-cmake	17m 15s
linux-gcc-cmake-unbundled	17m 2s
linux-gcc-make-cross-armhf	14m 47s
macos-clang-cmake-openssl3	21m 8s
macos-clang-cmake-openssl3-visibility-hidden	20m 30s
macos-clang-make	40m 18s
macos-clang-make-openssl3-tsan	21m 16s
macos-clang-make-openssl3-ubsan	34m 52s
macos-clang-make-visibility-hidden	28m 39s
linux-gcc-make-mongodb	8m 20s
linux-gcc-make-mysql	8m 22s
linux-gcc-make-odbc	13m 37s
linux-gcc-make-postgres	8m 14s
macos-clang-make-openssl3-asan	43m 59s
linux-gcc-make-redis	8m 20s
windows-2022-msvc-buildwin-x64	36m 26s
windows-2022-msvc-cmake	29m 33s
windows-2022-msvc-cmake-static	29m 17s
windows-2022-msvc-cmake-static-mt	23m 12s
linux-gcc-make-sqlite-no-sqlparser	8m 34s
	10h 58m 9s

Provide feedback