Fix "system.provisionSystem" xmlrpc endpoint to calculate kickstart host properly (bsc#1215209)

[meaksh]

What does this PR change?

This PR fixes an issue with system.provisionSystem endpoint, where the kickstart host that is used to generate tftpboot tree is calculated based on the hostname of the request, leading to wrongly assume localhost (and therefore generating wrong files) when connected to Uyuni XMLRPC API via localhost.

This PR makes this endpoint to use the same mechanism that the UI uses to calculate the kickstart host:

• If request is done via an Uyuni Proxy -> use the first proxy address in the chain of Uyuni proxies.
• Otherwise use default Cobbler host (Uyuni Server)

You can see the above mechanism implemented here: https://github.com/SUSE/spacewalk/blob/d4787b8757f0f5d2bbc56c5b325258349d56df09/java/code/src/com/redhat/rhn/frontend/action/kickstart/KickstartHelper.java#L258-L282

GUI diff

No difference.

• DONE

Documentation

• No documentation needed: only internal and user invisible changes

• DONE

Test coverage

• No tests: add explanation

• No tests: already covered

• Unit tests were added

• Cucumber tests were added

• DONE

Links

Tracks https://github.com/SUSE/spacewalk/issues/22528

• DONE

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[github-actions]

Suggested tests to cover this Pull Request

• minssh_salt_install_package
• srv_power_management
• min_bootstrap_api
• srv_sync_products
• min_bootstrap_reactivation
• srv_sync_channels
• proxy_cobbler_pxeboot
• srv_distro_cobbler
• min_rhlike_salt_install_package_and_patch
• minkvm_guests
• srv_handle_config_channels_with_ISS_v2
• srv_rename_hostname
• srv_enable_sync_products
• srv_cobbler_profile
• srv_monitoring
• min_deblike_salt_install_with_staging
• min_cve_audit
• min_ansible_control_node
• srv_power_management_redfish
• min_retracted_patches
• srv_user_configuration_salt_states
• min_activationkey
• allcli_action_chain
• min_salt_pkgset_beacon
• proxy_retail_pxeboot_and_mass_import
• proxy_branch_network
• min_bootstrap_script
• srv_virtual_host_manager
• min_cve_id_new_syntax
• proxy_register_as_minion_with_script
• min_deblike_salt_install_package
• min_salt_install_package
• buildhost_docker_build_image
• min_salt_migration
• srv_menu
• proxy_as_pod_basic_tests
• min_monitoring
• minssh_bootstrap_api
• srv_advanced_search
• srv_cobbler_distro
• srv_scc_user_credentials
• min_action_chain
• srv_first_settings
• minssh_action_chain
• srv_wait_for_reposync
• min_check_patches_install
• srv_maintenance_windows
• srv_cobbler_sync
• min_move_from_and_to_proxy
• min_salt_install_with_staging
• srv_cobbler_buildiso
• min_project_lotus
• min_ssh_tunnel
• min_salt_software_states
• min_config_state_channel_subscriptions
• minssh_move_from_and_to_proxy
• min_deblike_monitoring
• min_salt_mgrcompat_state
• allcli_software_channels_dependencies
• allcli_system_group
• srv_docker_cve_audit
• min_empty_system_profiles
• srv_reportdb
• allcli_reboot
• min_bootstrap_ssh_key
• min_rhlike_salt
• min_salt_formulas_advanced
• min_recurring_action
• min_salt_minion_details
• min_salt_lock_packages
• min_deblike_openscap_audit
• min_rhlike_ssh
• min_virthost
• min_salt_openscap_audit
• allcli_config_channel
• min_timezone
• min_rhlike_monitoring
• min_salt_user_states
• minssh_ansible_control_node
• min_deblike_salt
• buildhost_osimage_build_image
• buildhost_bootstrap
• min_rhlike_openscap_audit
• allcli_sanity
• min_deblike_ssh
• min_config_state_channel
• min_salt_minions_page
• min_change_software_channel
• sle_ssh_minion
• min_salt_formulas
• allcli_overview_systems_details
• min_custom_pkg_download_endpoint
• allcli_software_channels
• sle_minion

[github-actions]

👋 Hello! Thanks for contributing to our project 😄
☕ Acceptance tests will take same time (aprox. 1h)
👀 Once tests finish, you can check the cucumber report.
See the troubleshooting guide if you need any help.
⚠️ You should not merge if acceptance tests fail to pass
Happy hacking

[wweellddeerr]

Changes LGTM.