add support for booting windows pe and load the associated image drivers

[rgl]

this adds support for booting windows pe (tested with rgl/windows-pe-vagrant/).

you must also configure the image boot parameters to, including a initial blank line:

initrd {{BASE_URL}}/boot/{{CACHE_DIR}}/iso/Boot/BCD bcd
initrd {{BASE_URL}}/boot/{{CACHE_DIR}}/iso/Boot/boot.sdi boot.sdi

the boot menu entry (as returned by, e.g., curl http://localhost:8080/menu.ipxe) should look something like:

:iso17
echo Booting windows-pe-amd64...
echo Loading kernel and initrd...
echo Loading Windows boot files via wimboot...
kernel http://192.168.8.11:8080/wimboot 
initrd http://192.168.8.11:8080/boot/windows-pe-amd64/iso/Boot/BCD bcd
initrd http://192.168.8.11:8080/boot/windows-pe-amd64/iso/Boot/boot.sdi boot.sdi
initrd http://192.168.8.11:8080/boot/windows-pe-amd64/iso/sources/boot.wim boot.wim || initrd http://192.168.8.11:8080/boot/windows-pe-amd64/iso/SOURCES/BOOT.WIM boot.wim
boot || goto failed
goto start

PS I've also added the --windows-smb-port parameter value into the startnet.cmd:

$ docker exec bootimus wimextract /data/isos/windows-pe-amd64/iso/sources/boot.wim 1 /Windows/System32/startnet.cmd --to-stdout
...
net use Z: \\192.168.8.11\windows-pe-amd64 /persistent:no /tcpport:1445 >nul 2>&1
...

Setting the smb port is supported in windows since late 2024, which works on windows 11 24H2 (or later) or windows server 2025 (or later).

See https://learn.microsoft.com/en-us/windows-server/storage/file-server/smb-ports?tabs=command-line

PPS I've also added support for loading the associated image drivers (fixes #101). This will use PnPUnattend to detect and load the drivers in windows pe. Then use setup /installdrivers x:\drivers to load the drivers in the installed windows.

[garybowers]

looks good to me.