Migrate proto codegen tool from https://github.com/nspcc-dev/neofs-api-go

[cthulhu-rider]

https://github.com/nspcc-dev/neofs-api-go/tree/master/util/protogen was previously used. It's worth to migrate here with proper adoption: interfaces changed a bit, generics came into the game

make sure unit tests are max deep before, any mistakes in "stable" marshaling are critical. If they are not deep enough - increase coverage. I had several thoughts about this, will share a bit later

[roman-khimov]

1. Just transfer.
2. Separate issue for generics and any other magic.