Back in time, GRUB2 is using `linux` and `initrd` commands to load the kernel and initrd into ram on legacy BIOS.

Later, `linuxefi` and `initrdefi` commands have been added to do the same on UEFI platforms.

However, it looks like that `linuxefi` and `initrd` commands are deprecated and distributions like Ubuntu started to remove them starting with 24.04.

In case of Secure Boot [1] and Ubuntu 24.04 - putting corresponding shim+GRUB2 binaries in bootloader universe directory - the network boot is not working anymore because of used `linuxefi/initrd` commands in the involved GRUB2 configuration templates.

In order fix this we can simply add wrapper functions to provide `linuxefi`/`initrdefi` as commands. This saves us complicated conditions (like we do for AutoYAST and Kickstart templates) and works in any case.

[1]:https://github.com/theforeman/foreman/pull/9864