yac is built using preconfigured configure script and further flags added to yac and yaxt to bring it close to icon

lib64 folder added to fyaml-libs only if it exists (thank you levante); minor change to run on macos

cleaned up the partial building of deps via yac and made it entirely a user responsibility to manage the yaco deps enforced via the icon-stack

changed the way of handling yaco version in the yaco-build script to avoid extra step in the release

This reverts commit b5ff6ed0.

this has to be in line with the yaco config concerning time operations
and distribution of fields across yaco processes.