Make IngressClassV1 related functions in store.Store accept a class name argument

[pmalek]

Problem statement

store.Store's IngressClassV1 related functions do not accept ingress class as parameter. As of now this is not problematic but relies on filling store's ingressClass field.

We can make this more parametrized by using ingress class as parameter in IngressClassV1 related functions.

Acceptance criteria

• IngressClassV1 related functions in https://github.com/Kong/kubernetes-ingress-controller/blob/6988320be0b461f09a5213634a8be8bc39b549a6/internal/store/store.go accept an ingress class parameter
• Subsequently, a decision has to be made whether to pursue multiple ingress class support and appropriate comment with justification has to be posted in this issue.
  • If we decide to follow up this route then as part of this issue we have to create new issue to make appropriate changes in code (so that we do not piggy back on this one).

Additional information

Original comment this idea came from: Originally posted by @rainest in #2535 (comment)

[mflendrich]

@pmalek please scope this issue appropriately using the issue template. Looks like this is a part of a larger whole (that is, supporting multiple ingress classes within a single KIC) - please ensure that we have an issue trackign that larger effort as well.

[pmalek]

I've added acceptance criteria and reworded the issue statement.

[mflendrich]

No current demand for this feature, putting this in the freezer until further reevaluation.