Add support for Hermit Image decompression

[fogti]

Depends upon hermit-os/hermit-entry#61.

TODO:

• What allocator should be used for the decompressed bytes?
  • this is particularly important for UEFI, as we switch the global allocator there during boot.
  • Where do we get the start address for the one-shot allocator from?
  • Should we limit the maximum size that the one-shot allocator can allocate (besides the usize::MAX / 2 restriction)?
• FDT Bikeshedding / naming of entries
  • memory range of image (necessary because this is memory that can't be used by the kernel; chosen,image_reg: [u64;2] = (offset, length))
• boot_kernel for os=none (e.g. multiboot, firecracker, etc.) needs to gain an argument to pass an optional image range along. It might be a good idea to introduce a structure for "FDT parameters" to make further extensions easier in the future.

[fogti]

TODO: this might have to interact with the paging subsystem.

[fogti]

The boot_kernel functions appear to not be limited by cfg conditionals, so this is also unconditional, for now.

[fogti]

This is done because we can't change the alignment during reallocation/ growth.

[fogti]

Obvious mistakes — found via cargo xtask clippy — are fixed now.

[fogti]

TODO: fix non-UEFI version (currently, it should always panic) and test UEFI versoin (which should pretty much work as-is) using hermit-os/kernel#2077 as the kernel (using HERMIT_MANIFEST_DIR to specify a local checkout of that PR).