Allow a(aaa)_add with IP from non-existent network

[pederhan]

Adds the ability for the commands a_add and aaaa_add to add an IP from a network that cannot be found with -force. Previously, trying to add an IP from a network that could not be found raised a 404 error, which is not something we intended. This PR fixes that by using ok404=True in Network.get_by_ip().

All other calls to Network.get_by_ip expect it to return None when the network cannot be found:

mreg-cli/mreg_cli/commands/host_submodules/core.py

Lines 138 to 150 in c2df782

	if net_or_ip.is_ip() and not autodetect:
	ipaddr = net_or_ip.as_ip()
	try:
	network = Network.get_by_ip(ipaddr)
	if network:
	if ipaddr == network.network_address:
	raise InvalidIPAddress(
	f"IP {ipaddr} is a network address, not a host address"
	)
	elif ipaddr == network.broadcast_address:
	raise InvalidIPAddress(
	f"IP {ipaddr} is a broadcast address, not a host address"
	)

mreg-cli/mreg_cli/commands/host_submodules/core.py

Lines 156 to 163 in c2df782

	elif net_or_ip.is_network() or autodetect:
	network = (
	Network.get_by_ip(net_or_ip.as_ip())
	if autodetect
	else Network.get_by_network(str(network_or_ip))
	)
	if network:
	data["network"] = str(network.network)

mreg-cli/mreg_cli/commands/host_submodules/rr.py

Lines 540 to 542 in c2df782

	network = Network.get_by_ip(ip)
	if not network:
	raise EntityNotFound(f"{ip} isn't in a network controlled by MREG")

This PR now ensures the 404 error is handled when the network does, in fact, not exist.

[terjekv]

LGTM. Tests got canceled? :(