make spec.version required in Kiali CR and OSSMConsole CR

[jmazzitelli]

Now that we have many versions of Kiali, and OSSMC and backstage plugins, and they support different versions of Istio and each other, confusion is rampant among users :)

This is because if spec.version is not specified in the CRs, a default version is selected by the operator, and that version might not be compatible with the user's Istio or other Kiali components.

We need to make spec.version required. If not specified, the operator should immediately fail, and put a good error message in the status field of the CR letting the user know what they have to do.

• operator PR: require spec.version to be set in Kiali CR and OSSMConsole CR. kiali-operator#818
• helm PR: explicitly set spec.version in the CR helm-charts#283
• kiali.io docs PR: spec.version is required kiali.io#819

[jmazzitelli]

Note that we will still support the literal value default for spec.version (which we always have supported). This issue only concerns when there is no spec.version defined at all (it is completely missing from the Kiali CR).

[jmazzitelli]

@nrfox and @ferhoyos are -1 on fixing this.
I am +1.

We need more votes. Others, please chime in.

If we get a quorum and the consensus is to do nothing, I can close this issue and cancel the PRs.