Add Optional Restricted Network Check

[komish]

This PR is built off of the lib-->main rebase because that rebase has moved a majority of the library code into an internal package. This PR does the same for new code to avoid rework. If you want to review this before that merge happens, just click on the last commit of this commit stack, which should show you only the changes actually associated with this PR (e.g. b05a562 but this will change as I fix bugs)

---

This PR adds a check that attempts to review a CSV for hints that the developer has implemented guidelines to support clusters that have restricted networks. This boils down to:

• Does the operator have related images defined in their CSV spec. There's already a related image check, so we do not replicate that work, but instead just do a soft check to make sure there are values in that section.
• Does this operator have the "disconnected" infrastructure-feature annotation.
• Does this operator include environment variables in any of its deployment containers that are prefixed with RELATED_IMAGE_, indicating that the developer intends to pass through (to the controller) what images it should use for its managed workloads.

There's no technical way to validate that the third bullet results in a workload that respects this value. With that being said, OperatorSDK and operator-manifest-tools will automatically pin tagged images to their digest values if they're prefixed with this string, and so it makes sense to at least look for them to try to increase the confidence that things will work as expected.

This check is marked as optional. It may fail, but that failure does not block overall results, or reflect as a failed check.

---

Note that a majority of this check's logic was thrown into a library (internal/csv) just to make it easier to test.

[komish]

/hold

[dcibot]

• SUCCESS https://www.distributed-ci.io/jobs/50c8e1a2-b44f-47e6-b624-660d70b584e3/jobStates
  from Add Optional Restricted Network Check #858

[acornett21]

My comments ended up on the commit and not this PR. :(

Summary:

• A few nonblocking nits.
• My main issue is that how validate has to be implemented to conform to our validate style (and go's coding style), we are going to be catering to the 1% of operators that pass through validate completely. Then the 99% of operator owners are going to see a bunch of warnings in their logs that are completely confusing. I feel this is going to lead to a far number of support cases.

[komish]

357e60c addresses golangci-lint complaints

[coveralls]

coverage: 74.378% (-7.4%) from 81.77%
when pulling 9dd58dd on komish:add-restr-net-check
into 8d6f8de on redhat-openshift-ecosystem:main.

[komish]

The 2.5% coverage decrease is also coming from the original commits related to the rebase - not this PR.

[dcibot]

• SUCCESS https://www.distributed-ci.io/jobs/f58202b7-4bb3-48da-a0cd-cc403fde4e31/jobStates
  from Add Optional Restricted Network Check #858

[komish]

Removing the hold on this as lib-->main has now merged, and this should no longer reflect those changes in this PR's commit history. Just the relevant changes.

[dcibot]

• SUCCESS https://www.distributed-ci.io/jobs/10f1dbb6-f561-4d0b-84fd-c5e8485beb44/jobStates
  from Add Optional Restricted Network Check #858

[bcrochet]

A nit, a question, and a bug.

[dcibot]

• SUCCESS https://www.distributed-ci.io/jobs/9ad31426-4fd6-42bc-90f6-37a27d26a878/jobStates
  from Add Optional Restricted Network Check #858

[dcibot]

• SUCCESS https://www.distributed-ci.io/jobs/f7cb0558-ad51-4267-8a1e-fb2f41936210/jobStates
  from Add Optional Restricted Network Check #858

[bcrochet]

Just a small nit. I'll drop an approve in case you want to ignore it.

[acornett21]

/lgtm

[dcibot]

• SUCCESS https://www.distributed-ci.io/jobs/2c3732d4-c15c-4a09-bf33-297a45acd32a/jobStates
  from Add Optional Restricted Network Check #858

[bcrochet]

/lgtm

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: acornett21, bcrochet, komish

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [acornett21,bcrochet,komish]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment