Add a unicode font file and other useful modules to make gfxterm etc available.

I don't think this process of appending modules is very scalable.
Should probably investigate implementing a mechanism in the base
grub-efi recipe to allow these to just be built into the base efi
binary.
Move syslinux.cfg to a file instead of echoing text. Requires a few OE odities to get fetch/unpack to work as expected.
Add modules to boot image so grub config can load them.
measured-image-bootimg: Move grub.cfg to a separate file.