cloud-setup: add tool for automatic IP configuration in cloud

This is a tool for automatically configuring networking in azure
cloud environment.

This add a provider implementation for Azure that when detected fetches
the private ip addressess and the subnet prefix of configured internal
load balancers.

Once this information is fetched from the metadata server, it instructs
NetworkManager to add private ip addressess and subnet prefix for each
interface detected.

It is inspired by SuSE's cloud-netconfig ([1], [2]) and Azure Instance Metadata service [3].

[1] https://www.suse.com/c/multi-nic-cloud-netconfig-ec2-azure/
[2] https://github.com/SUSE-Enceladus/cloud-netconfig
[3] https://docs.microsoft.com/en-us/azure/virtual-machines/linux/instance-metadata-service

It is also intended to work without configuration. The main point is
that you boot an image with NetworkManager and nm-cloud-setup enabled,
and it just works.
20 jobs for ss/azure-cloud-setup in 30 minutes and 12 seconds (queued for 3 minutes and 26 seconds)
latest
Status Job ID Name Coverage
  Test
passed #3855210
checkpatch

00:01:11

manual #3855217
allowed to fail manual
t_centos:7.5.1804
manual #3855218
allowed to fail manual
t_centos:7.6.1810
manual #3855219
allowed to fail manual
t_centos:7.7.1908
manual #3855220
allowed to fail manual
t_centos:7.8.2003
manual #3855221
allowed to fail manual
t_centos:8.1.1911
manual #3855227
allowed to fail manual
t_debian:10
manual #3855226
allowed to fail manual
t_debian:9
manual #3855229
allowed to fail manual
t_debian:sid
manual #3855228
allowed to fail manual
t_debian:testing
manual #3855211
allowed to fail manual
t_fedora:28
manual #3855212
allowed to fail manual
t_fedora:29
manual #3855213
allowed to fail manual
t_fedora:30
passed #3855214
t_fedora:31

00:30:11

manual #3855215
allowed to fail manual
t_fedora:32
manual #3855216
allowed to fail manual
t_fedora:rawhide
manual #3855222
allowed to fail manual
t_ubuntu:16.04
manual #3855223
allowed to fail manual
t_ubuntu:18.04
manual #3855225
allowed to fail manual
t_ubuntu:devel
manual #3855224
allowed to fail manual
t_ubuntu:rolling