Google AEC rework: dynamic formats, legacy platform support

[andyross]

This is almost exactly the code as it stands in PR #8571, but rebased on top of current main (which descends from mtl-008-drop-stable) and with as many individual changes split out as I could. Basically this unbreaks AEC for IPC3 targets (mt8195 in particular) with a unified implementation, supports dynamic stream sample formats, improves performance and code size significantly, and removes a few hundred lines of duplicated/unparametrized code. Tested on mt8195 and MTL, will pull out a ADL board and try that as soon as I get a chance.

See individual patch commit messages for more details.