Error handling for FindCatalogSourceByName

[nasark]

The FindCatalogSourceByName was returning an empty catalog source object if the catalog source was not found instead of returning nil i.e. (from debug logging)

{"result": {"metadata":{"creationTimestamp":null},"spec":{"sourceType":"","icon":{"base64data":"","mediatype":""}},"status":{}}}

This was nullifying the openshift checks we have in place for deploying the strimzi operator https://github.com/ManageIQ/manageiq-pods/blob/master/manageiq-operator/internal/controller/manageiq_controller.go#L529

In addition it was found that the following error is thrown if performing a client.Get() call on a resource for which the CRDs are not installed (instead of throwing errors.IsNotFound()):

failed to get restmapping: no matches for kind \"CatalogSource\" in group \"operators.coreos.com\"

This occurs when using plain k8s as the openshift CRDs (operators.coreos.com) are not installed

@miq-bot add_labels bug, quinteros/yes?
@miq-bot assign @bdunne
@miq-bot add_reviewer @Fryguy

Ref: #1043

[miq-bot]

Checked commit nasark@6bbdbe3 with ruby 2.7.8, rubocop 1.56.3, haml-lint 0.51.0, and yamllint
0 files checked, 0 offenses detected
Everything looks fine. ⭐

[Fryguy]

Backported to quinteros in commit 0b59f67.

commit 0b59f6762f7fc60d648ec23c83bacfbbb1bbb765
Author: Brandon Dunne <brandondunne@hotmail.com>
Date:   Tue Jan 30 16:32:25 2024 -0500

    Merge pull request #1044 from nasark/findcatalogsource_error_handling
    
    Error handling for FindCatalogSourceByName
    
    (cherry picked from commit 0d1c69b871f5deb3b7a2038a06f30d7b1fffb426)