See merge request nexedi/slapos!1130

The test name (and shared instance name) was misleading.

The test have incorrect leftover of old limited implementation, now the system
shall update images by itself.

Also the typical scenario - image on first request - was not covered.

Adapt the test to code without needed linking.

image-download-controller raises error state during download process, to
inform other components that download is not ready yet.

template-kvm-run.in asserts presence of all images and otherwise refuses to
start, so that it gives chance for the image to being downloaded.

Sorting images happen by proper key instead of needless links.

Fix race condition, as the hash parameter shall depend on boot image url
configuration, and not it's failure state.

Cleanups:

 * simplify nginx management with real template
 * rename sections to provide explanation in their name so it's less cryptic

Instead of trusting CSR id published by the node which tries to join the
cluster add a tool which is able to compare exposed CSR with one in caucase
and then decide to accept node in the cluster. This tool does what usual user
would do, and it's logic implemented as a script leads to much simpler profiles.

For sake of clean profiles csr_id has been removed, except when it's used for
self joining of the user to the cluster.

Adjust paths.
Cleanup.

Use relative paths. Cleanup.

CSR id shall be requested only when it's not available yet, as otherwise it
contacts caucase server needlessly, and in some circumstances it can result
with bogus new CSR.

Fixes a build error with recent gawk versions.

As refernce to the network-config-ipv4 part has been removed from the
publish-connection-information the part was not installed anymore, so the
netconfig.sh file was not added.

Fixed it by simply adding this part to the installed ones.

This fixes commit 3f7d8965

Server header might be changed by client facing caddy, for which caddy code
has been fixed to not transmit the Server header at all by default.
In ATS Server header has been disabled by configuration.
haproxy does not add Server header at all.
Thanks to improvement in the test backend, it's asserted that Server header
send by the backend is left intact.

This was useless. dumps is enough.