Fixes#2363#2364#2370#2371
Several changes packed together:
* use compressed `vmlinuz` everywhere, firecracker provisioner
uncompresses it before first use, drop `vmlinux`
* handle reboots in qemu launcher to support reset API case, update
empty disk check to handle reset behavior (erasing partition table)
* make bootloader support default in provisioners, and flag to disable
that
* early support for target architecture for qemu provisioner
This should allow us to use `qemu` in CI/CD (not included into this PR):
integration test passes with qemu.
Signed-off-by: Andrey Smirnov <smirnov.andrey@gmail.com>
a5d64d97c1