Improve Azure deployment reconciler and add tests

[matthchr]

What this PR does / why we need it:

• Fixes a number of issues with the Azure deployment reconciler.
• Adds various edge-case tests to ensure that scenarios such as creating
  a resource before it's owner is created, or updating a failed resource, work
  correctly.

How does this PR make you feel:

If applicable:

• this PR contains documentation
• this PR contains tests

[matthchr]

Ignore the first commit (based on my VMSS branch, will go away once that merges).

This is a draft PR just so folks are aware of the upcoming tests and changes. I think after this we should have enough test coverage to be more confident about the reconciler behavior.

Thinking we can follow this PR up with some refactoring around:

1. Resource states
2. Code structure in the reconciler

[codecov-commenter]

Codecov Report

Merging #1605 (b5b0021) into master (0b5e1f2) will increase coverage by 0.53%.
The diff coverage is 74.54%.

❗ Current head b5b0021 differs from pull request most recent head 12d7d54. Consider uploading reports for the commit 12d7d54 to get more accurate results

@@            Coverage Diff             @@
##           master    #1605      +/-   ##
==========================================
+ Coverage   62.38%   62.91%   +0.53%     
==========================================
  Files         186      187       +1     
  Lines       12273    12355      +82     
==========================================
+ Hits         7656     7773     +117     
+ Misses       3926     3898      -28     
+ Partials      691      684       -7     

Impacted Files	Coverage Δ
...d/pkg/testcommon/error_translating_roundtripper.go	10.00% <0.00%> (-3.34%)	⬇️
hack/generated/pkg/armclient/types.go	78.02% <33.33%> (+4.15%)	⬆️
...generated/pkg/testcommon/be_provisioned_matcher.go	22.22% <60.00%> (+2.99%)	⬆️
hack/generated/pkg/testcommon/ensure.go	46.87% <66.66%> (+0.20%)	⬆️
...ted/pkg/reconcilers/azure_deployment_reconciler.go	66.58% <81.25%> (+10.50%)	⬆️
...ted/pkg/reconcilers/deployment_error_classifier.go	88.88% <88.88%> (ø)
...ck/generated/pkg/reflecthelpers/reflect_helpers.go	62.88% <100.00%> (+2.06%)	⬆️
hack/generated/pkg/testcommon/kube_matcher.go	100.00% <100.00%> (ø)
.../generated/pkg/testcommon/kube_per_test_context.go	80.48% <100.00%> (+0.82%)	⬆️
... and 6 more

---

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[theunrepentantgeek]

Some minor suggestions, but otherwise looks good.

[theunrepentantgeek]

Suggested change

	// State checks to ensure the provisioning state of the resource the target state.
	// State checks to check whether the provisioning state of the resource has the target state.

"Ensure" is an active word that implies this method will make any changes required for the resource to be in target state; I don't think that's what you mean.

[theunrepentantgeek]

Maybe call the method HasState()?

[matthchr]

"Ensure" is an active word that implies this method will make any changes required for the resource to be in target state; I don't think that's what you mean.

The actual struct is already called Ensure - but the methods hanging off as you note do not actually make changes, they just check them. This same comment style is repeated for the other methods Provisioned, Failed, etc.

Merriam-Webster says:

Ensure: to make sure, certain, or safe : guarantee

whereas Cambridge dictionary agrees with you:

To make something certain to happen

I'm going to hold off making a change on this - if we do want to change it we should change the whole class, not just this one place, and it probably ought to be done in a separate PR

[matthchr]

Changed to HasState

[matthchr]

I made a note to change Ensure to something else, maybe Verify? Will do it when I have some spare time.