Always create all host groups in mapping file

[pederhan]

As of now, for a host group to be created, at least one host must exist with one of the host group's site admin addresses assigned to it. This makes it impossible to pre-emptively create host groups before hosts have been created/assigned.

To change this, we need to refactor some of the code in ZabbixHostgroupUpdater.do_update():

zabbix-auto-config/zabbix_auto_config/processing.py

Lines 1072 to 1079 in 2650598

	for hostgroup_name in synced_hostgroup_names:
	if hostgroup_name not in host_hostgroups.keys():
	logging.debug("Going to add hostgroup '%s' to host '%s'.", hostgroup_name, zabbix_hostname)
	zabbix_hostgroup_id = zabbix_hostgroups.get(hostgroup_name, None)
	if not zabbix_hostgroup_id:
	# The hostgroup doesn't exist. We need to create it.
	zabbix_hostgroup_id = self.create_hostgroup(hostgroup_name)
	host_hostgroups[hostgroup_name] = zabbix_hostgroup_id

Specifically the bit around creating groups when fetching the Zabbix group ID for a specific group. We could likely just loop through all groups and create them before we assign them to hosts.