Remove CSVConfig and use CSV Generator for configurable inputs and output

[hasbro17]

Description of the change:
Continuation of #2407 to implement the CSV generator.

• cmd/operator-sdk/olmcatalog: remove config flag, add include flag, use CSV and package manifest generators

• internal/generate/olm-catalog: implement CSV generator, moving most of the code from internal/scaffold/olm-catalog verbatim. Also removed CSV config

• doc: remove CSVConfig documentation, update CLI docs

Currently this gets #2407 rebased with the master and breaks up the internal/generate/olm-catalog pkg changes, and the internal/generate/testdata/ manifests changes into separate commits for ease of reviewing.

TODO:

• Change --include flag to --inputs to allow configuring the CSV generator Inputs field for Deploy and API directory paths e.g:
  --input deploy=./deploy/production/...,apis=./pkg/apis
• Remove Filters field from generator config since its UX was ambiguous
• Add flag --outputDir to set CSV Generator Output field to set the output root directory for the olm-catalog bundles directory.

Motivation for the change:

Resolves #2493

[hasbro17]

@estroz No need to review until I finish the TODOs but a quick sanity check over the first commit would be helpful to ensure I've carried forward the necessary changes from #2407

Had to untangle that PR a bit to rebase and split up the commits since quite a few changes from that had already gone into master.

[estroz]

Looks like you got everything. I would remove the Helm tests from this PR and make a follow-up (that was my plan but I didn't get around to it).

[hasbro17]

Yeah I'll remove the Helm tests from this. I initially split it up as a separate commit but a follow up would be easier to review.

[hasbro17]

@estroz I've done some manual tests and have this mostly working.
I still need to clean up a couple of things plus update the unit tests, but I've got a couple of questions that came up as I was refactoring.
I've marked them as TODO comments if you could take a look at those. Just the 2nd commit which has my changes to your old PR.

[openshift-ci-robot]

New changes are detected. LGTM label has been removed.

[hasbro17]

Sigh
@estroz Any clue why the scorecard test for bundle validation might be failing? I'm not sure if after rebasing from master if the scorecard now relies on any testdata manifests that I've modified/moved around in this PR.
https://travis-ci.org/github/operator-framework/operator-sdk/jobs/669505119#L1244

olm:
	Bundle Validation Test              
	CR: example-memcached
	Labels: 
		"necessity":"required"
		"suite":"olm"
		"test":"bundlevalidationtest"
	Errors: 
		unable to find the OLM '\''bundle'\'' directory which is required for this test
	Provided APIs have validation       pass
	CR: example-memcached
	Labels: 
		"test":"crdshavevalidationtest"
		"necessity":"required"
		"suite":"olm"

Or if scorecard is using generate csv to generate the bundle directory and somehow failing to.
Going to dig into this a bit.

[hasbro17]

@estroz Thanks for the fix 🙏
Had to reset CI a few times to get marker to play nice but all clear in the end.