It’s called AMCO, and it’s fairly modular in that you can use the base movement animations with any of the several dozen attack animations on Nexus.
There’s also a mod which applies all this to NPCs as well. (If I recall, it’s called SCAR, but I’m not certain because it’s been quite a while.)
Main site (with a whole bunch of related mods): https://www.skyrim-guild.com/mods/category/Combat
There are also related videos on each mod’s page showing what they do.
Enjoy!