add default_namespaced - for #209

[clux]

based on suggestion in #394 (comment)

WIP. POC there, but missing some tests. And probably need to test through Api, which makes this a completely new test path.

[clux]

Not sure I need to do it this way. I have the Client, and it should have the default_ns set at this point. Could possibly just do #209 (comment)
EDIT: no i am tired.

[clux]

Going to wait with this a bit. It's awkwardly coupling Api and Service in a way that requires an entirely new way to test.

I think having a way to test the Client would be useful, but am going to explore that before merging this so we can have some tests on it.

#[test]
fn api_default_ns() {
    use k8s_openapi::api::core::v1::Pod;
    let client = Client::mock();
    let pods: Api<Pod> = Api::default_namespaced(&client);
    let _p = api.get("blod").await?
    // TODO: intercept outgoing call and inspect request elements

    // TODO: verify request url has updated the default namespace (set to non-default in Client::mock)
}

It's possible it's necessary to copy default_ns into Client so that Api::default_namespaced can use a getter on the Client instead. Not elegant, but it gets rid of the coupling.

Anyway going to experiment a bit with mocks first.

[clux]

Replaced by #534