- Remove false positive report of not enough space on multiples of 4KB
   size (by changing to 64KB multiples)
   o Still probably a false positive if original ROM size (which is
     normally a multiple of 512 bytes anyway) is exactly 128KB, since
     normal total Nvidia VBIOS space is at least 256KB, but...
 - Allow Nvidia max size override
 - Fix no overflow check against true max., if size is not a multiple
   of 4KB (now 64KB)
   o We would not have hit this in practice before, given actual ROM
     sizes and actual least available max of 256KB

Since nvflash dumps and writes back the whole ROM, and since we are
often (and safely) starting with a ROM below 128KB and ending up with
one above it, there is no need to try to limit Nvidia ROMs when the initial
ROM is a round size. (nvflash will refuse to write it back if it is too large;
anything else, such as a first part which becomes too large and overwrites
a useful second part, should not happen; this is unlike AMD where all
changes have to happen within the first 128KB, and anything above 128KB
should not be moved, and is not mapped to memory visible by the CPU.)

apfs.efi has W^X errors which require fixup for strict loaders, however
we were only passing the post-sanitised image to OC-wrapped
platform loader, therefore the wrapper in ImageLoader.c cannot
detect that it is an Apple signed binary which should be fixed up.

BuiltinPicker: Avoid responding to possibly multiple keys pressed before menu is read out, if using audio assist

when these are being read out due to audio assist

It is still needed on some systems such as Acer E5 where DisconnectHda
does not work.

Works round fact that OpenCore XML parser does not
automatically decode any XML entities.