tests/functional: Convert Aarch64 Virt machine avocado tests

tests/functional: Convert Aarch64 Virt machine avocado tests

Straight forward conversion. Update the SHA1 hash to
SHA256 since SHA1 should not be used anymore nowadays.

Provide get_qemu_img() helper in qemu_test.

  $ make check-functional-aarch64 V=1
  ▶ 1/4 test_aarch64_virt.Aarch64VirtMachine.test_aarch64_virt_gicv2                 OK
  ▶ 1/4 test_aarch64_virt.Aarch64VirtMachine.test_aarch64_virt_gicv3                 OK
  ▶ 1/4 test_aarch64_virt.Aarch64VirtMachine.test_alpine_virt_tcg_gic_max            OK
  1/4 qemu:func-thorough+func-aarch64-thorough+thorough / func-aarch64-aarch64_virt  OK   30.44s  3 subtests passed
  ...

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240826103634.52384-1-philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-ID: <20240830133841.142644-36-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>