qemu_guest_agent: Add ssh-key injection support for windows #6796

Job	Run time
Commit lint	14s
PR title	1s
Cfg lint	9s
Python 3.6	1m 16s
Python 3.9	1m 32s
Cartesian syntax (qemu/tests/cfg/qemu_guest_agent.cfg)	7s
	3m 19s

Provide feedback