(#16327) Fix fact terminus configuration cache handling

The facts terminus had a hook intended to configure the local YAML cache when
a remote terminus was in use. This worked as expected back in the 2.7 days,
but other changes have shifted it since then - and now it wasn't getting
invoked at the correct time to handle other configuration option changes.

This changes it to run the hook every time the terminus is changed, restoring
the correct behaviour when `facts_terminus` is set in the configuration file.

Signed-off-by: Daniel Pittman <daniel@puppetlabs.com>
(#16327) Continue agent run when node terminus find fails

When the agent starts a run it tries to fetch node data, in order to obtain
from the master idea of the environment it should be running in.  This allows
an ENC to fully control the environment of the agent.

If that isn't possible the agent can carry on - it may obtain a catalog in the
wrong environment, which will require that it fetch the catalog a second time,
so is quite a potential performance cost, even if a rare one.

Previously exceptions from the node terminus would abort the agent run, which
included cases where the terminus on the master failed to fetch data.

The case that discovered this was the `inventory_service` terminus for facts:
it was built with the assumption that it used a local YAML cache on the
master, and also talked to the remote server.

This was "too robust to fail" because the first time facts were found was
after they had just been saved in the compiler - an invariant that was true
until the agent started asking for the node definition.

In the case that no ENC was in use, and the inventory service was down,
though, the find operation would actually hard-fail, and that exception came
back down to the agent - and aborted the run.

This meant that it was impossible to bootstrap a node when the inventory
service was down: until you had submitted facts you couldn't get the node
data, but until you got node data the agent would never submit facts.

This simply expands the tolerance of the agent to node lookup failures:
because the worst case is that we compile the catalog a second time, in the
rare case of mismatch *and* your external service being down, this is
fairly safe.

Certainly, much safer than simply ignoring the node definition error on the
server, or not reporting it to other API consumers - who may actually care to
know that they couldn't get the data, or may not be able to operate
without it.

Signed-off-by: Daniel Pittman <daniel@puppetlabs.com>
(#16120) ips package provider gets feature holdable.

Previously the ips package provider did not provide the feature holdable.
This update brings the feature holdable to ips packaging and adds test cases
to check for this feature.
(#16120) ips package provider gets feature holdable.

Add the missing test case to specs.
Merge pull request #1149 from vrthra/ticket/3.x/16120_add_holdable_ips

(#16120) ips package provider gets feature holdable.
Same commits (same sha) was merged in This was merged into master in  <https://github.com/puppetlabs/puppet/commit/d15e83f57ce70058a5efeb78ade0299a5bd22070>
Merge pull request #1145 from daniel-pittman/bug/3.x/16327-inventory-service-fails-when-target-is-absent

#16327: inventory service fails when target is absent
Merge remote-tracking branch 'upstream/3.x'

* upstream/3.x:
  (#16120) ips package provider gets feature holdable.
  (#16120) ips package provider gets feature holdable.
  (#16327) Continue agent run when node terminus find fails
  (#16327) Fix fact terminus configuration cache handling