[Windows] Use hpc base image and buildx to build Agent Windows image

[wenyingd]

The changes in this patch include,

1. Use Windows hpc as the base image to store Antrea binary and OVS files
2. Use doocker buildx to build Windows image on Linux base environment
3. Modify OVS init container to install redist files
4. Place openssl dll files into OVS binary directory instead of Windows system path

Using the hpc base image and buildx on a fresh env, the time to build Windows related images is as follows,

1. windows-ovs: 22.4s
2. windows-base: 15s
3. antrea-windows: 190s

Fix #6311