Add flags to reconcile one specific Gateway only

[mlavacca]

Is there an existing issue for this?

• I have searched the existing issues

Problem Statement

In the context of the KGO's managed gateways, we need to configure KIC such that only a specific Gateway is reconciled. In that scenario, there is a 1:1 relationship between KIC and a Gateway API Gateway.

Proposed Solution

• add a new gateway-name and gateway-namespace flag
• if the gateway-name flag is specified but the gateway-namespace flag is unset, the namespace is inferred by the controller namespace (POD_NAMESPACE env)
• add a new namespacedName field in the Gateway API reconcilers. and configure it with the above values
• only resources managed by the specified Gateway are reconciled by the Gateway API controllers

Additional information

No response

Acceptance Criteria

• as a user, I'm able to set a specific Gateway that KIC will reconcile

[tao12345666333]

Let me pick up this one.