Refactors the core guest memory access subsystem (guest.h) to be safer
and portable accross host systems with different endianness. The
previous implementation used direct pointer casting, which is not endian
safe.
1. All read and write functions have been converted from unsafe pointer
casts to memcpy(). This resolves alignment warning -Wcast-align.
2. The access functions no longer rely on asserts for error checking.
They now perform explicit boundary and alignment checking and returns
a guest_mem_access_result_t status code.
3. A new header (endian.h) provides cross platform byte swapping macros.
The memory access functions use these macros to ensure that the guest
always sees memory in the correct endian format, regardless of the
host's native byte order. The host endianness is now automatically
detected via CMake.
3. Asserts are now explicitly enabled in release builds to catch
critical errors.
Signed-off-by: Ronald Caesar <github43132@proton.me>
