efi-defs library to make UEFI applications easier

As part of an effort to make Stem and Rootloader a tad bit cleaner, I have seperated their efi header definitions and utils functions into a new library.

The new efi-defs library allows anyone to more easily build UEFI applications without having to worry about finding/creating a header file that defines all UEFI structures and UIDs.

efi-defs is different from other UEFI libraries like gnu-efi in the sense that efi-defs is meant to be purely UEFI definitions and some tiny utility functions related to UCS-2 string handling.

Both Stem and Rootloader have moved to using efi-defs and can be used as examples on how to utilize efi-defs.

References

efi-defs Repository: git.pinkro.se codeberg

gnu-efi Repository: github