refactor: use simd bit packing for index #900

Job	Run time
Mac (macos, 12, 5.15.2, x64, macos-qt5, -DKLOGG_OSX_DEPLOYMENT_TARGET=11.7)	9m 11s
Linux (oraclelinux, 8, x64, yum install -y --setopt tsflags=test /usr/local/klogg*.rpm, RPM, orac...	13m 43s
Mac (macos, 12, 6.7.3, qt5compat, x64, macos-qt6, -DKLOGG_OSX_DEPLOYMENT_TARGET=11.7)	10m 36s
Windows (windows, 2022, 6.7.3, qt5compat, x64, -x64, windows-x64-qt6)	10m 6s
SaveVersion	5s
Linux (ubuntu_focal, 20.04, x64, apt-get update && apt install --dry-run /usr/local/klogg*.deb, D...	18m 57s
Windows (windows, 2022, 5.15.2, x64, -x64, windows-x64-qt5)	9m 37s
Linux (ubuntu_jammy, 22.04, x64, apt-get update && apt install --dry-run /usr/local/klogg*.deb, D...	11m 58s
Windows (windows, 2022, 5.15.2, x86, win32_msvc2019, windows-x86-qt5)	6m 23s
Linux (ubuntu_noble, 24.04, x64, apt-get update && apt install --dry-run /usr/local/klogg*.deb, D...	14m 8s
Linux (ubuntu_appimage, 20.04, x64, appimage, AppImage, docker/ubuntu20.04_qt5.15, variar/klogg_u...	10m 45s
	1h 55m 29s

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