Do not guess resource endpoints

[MikailBag]

Currently Resource (which is the only entity that is actually working with Kubernetes URLs) only known resource kind (such as "Pod"). However, URLs contain resource name instead (e.g. "pods" or "statefulsets"). Resource uses inflector crate to pluralize the kind and assumes that is it valid resource name. Although it works for most of resources, this means that is impossible to use Client with resources that do not follow this scheme (no matter are you using typed Api<k8s_openapi::Foo> or untyped Api<DynamicObject>). Just several examples of such resources:

• discovery.k8s.io: EndpointSlice is served on endpointslices, but inflector guesses endpointsliceice.
• metrics.k8s.io: NodeMetrics is served on nodes, and PodMetrics is served on pods. Impossible to guess.

It seems that in typed case we can't get rid of inflector until k8s-openapi provides us with this information, but at least dynamic API should work without guessing URLs.

[MikailBag]

My proposal:

• Add new resource_name (or endpoint, I'm not good at naming) method to the Meta trait.
• Add a name field to GVK.
• impl Meta for DynamicObject is changed to return this name.
• impl Meta for K where K: k8s_openapi::Resource still uses inflector
• When at some moment k8s-openapi provides resource name, we just change that method to use this provided information instead of the calls to inflector.

[clux]

Yeah, we know this is bad. It's #284. Was hoping we'd get a fix in k8s-openapi, but no one has jumped on the issue there yet.

I think your proposal is reasonable. Now that Meta is unchained from k8s-openapi we can define what we want, and it seems a good place to start by fixing it there, and having the other one fallback to inflector for now.

We could potentially do one better by tackling cluster/namespaced scoping as part of the trait (see #199) as well (although one for a separate PR i think).

[clux]

As for naming; plural is probably what we want. It's what's used in kube-derive.

[kazk]

whatisinternet/Inflector#73 fixes the iceice, but Inflector is no longer maintained. It's also a large dependency, and we don't need most of its features.

Do we have any irregular plurals to handle? I feel like we can use a much simpler function to handle basic pluralization instead.

[clux]

No longer guessing unless we have to from 0.52.0