Add streaming list support to WatchParams

[clux]

What problem are you trying to solve?

Supporting streaming lists on kubernetes > 1.27 https://kubernetes.io/docs/reference/using-api/api-concepts/#streaming-lists

Describe the solution you'd like

The initial support of this does not need to touch the watcher (#1209 has higher level discussion) nor Api::watch. Adding the flag to WatchParams is sufficient to support it:

• Wait for a k8s-openapi release with 1_27 support (reason for blocked)
• Add send_initial_events: bool to WatchParams in params.rs in kube-core
• Hide it behind a k8s_openapi::k8s_if_ge_1_27 macro
• Add a WatchParams::initial_events() builder that allows turning it on easily
• Test that it gets added to query strings in requests.rs in kube-core (also gated by 1_27 macro)
• Make an example use it. maybe event_watcher.rs

Describe alternatives you've considered

None, new feature, should be supported.

Documentation, Adoption, Migration Strategy

Straight addition. Just make sure we hide it and tests under the k8s_openapi 1_27 feature. Integration tests are already using >=1.27 so we are just waiting for a k8s-openapi release to give us the standard macro.

Target crate for feature

kube-core