Install aarch64 guests on SL Micro 6.1 aarch64 host

[waynechen55]

• Install aarch64 guests, including SL Micro 6.1 from raw and qcow2 disk images and SLE 15-SP6 from medium repository, on SL Micro 6.1 aarch64 host.

• New guest profiles for aarch64:

  • sles_15_sp6_64_kvm_hvm_uefi_without_power_management_aarch64.xml
  • slm_6_1_64_kvm_hvm_aarch64_default_qcow_ignition+combustion.xml
  • slm_6_1_64_kvm_hvm_aarch64_default_raw_ignition+combustion.xml

• New guest autoyast template for aarch64:

  • sles_15_plus_kvm_hvm_guest_graphical_aarch64.xml

• Add sle-module-python3 in guest autoyast template, otherwise registration will fail due to missing extension.

• This pull request can only be merged after verifying bsc#1229131.

• Verification Runs:

  • uefi sles15sp6 on sles15sp6 kvm x86_64
  • uefi sles12sp5 on sles15sp6 xen x86_64
  • uefi sles15sp5 on sles15sp6 xen x86_64
  • sl-micro 6.1 on sl-micro 6.1 aarch64
  • sles15sp6 on sl-micro 6.1 aarch64