Support for Petalinux 2023.2

• Change HDF integration (from env vars to Jinja2 templates): scr/yocto/hdf_recipe_macros.jinja2, scr/yocto/hdf_recipe_gen.py
  • Fixes HDF versioning which was broken before
• Add skeleton code & scaffolding to set up Yocto config & HDF integration for new projects: scr/yocto/meta-hdf-skel, scr/yocto/cfg-skel, scr/yocto/init_fwfwk_yocto.sh
• Various QOL improvements in yocto.mk
  • Add cfg/yocto_site.conf to separate project setup from build site setup
  • Add make_fitimage target
  • Remove bitbake alias function in favor of a generated local.conf (enables all other Yocto tools such as bitbake-layers, devtool et al which were broken before)