Create a simple k8s job that can install or upgrade Gateway API CRDs

[bharathbrat]

What type of PR is this?
/kind feature

What this PR does / why we need it:

This code provides a safe, automated mechanism to install and upgrade Gateway API Custom Resource Definitions (CRDs) using Kubernetes Jobs. It enforces a strict
"standard-channel-only" policy to prevent accidental downgrades or channel conflicts (e.g., Experimental vs. Standard).

The solution offers three modes of operation:

1. List: Reports the version and channel of all currently installed Gateway API CRDs.
2. Upgrade Existing: Scans the cluster for installed CRDs and upgrades them if a newer version is requested.
3. Install/Upgrade Subset: Installs or upgrades a specific list of CRDs defined by the user.

More details and test log in this document: https://docs.google.com/document/d/1th_QTfO6I7t7l1EVe7yppwtwyDSVO34RSd9_FBsC9Z4/edit?usp=sharing.

Which issue(s) this PR fixes:

Fixes #2678

Does this PR introduce a user-facing change?:

Gateway API CRD Installer: Safe CRD Upgrade Job

This release introduces a dedicated Kubernetes Job to safely manage the lifecycle of Gateway API CRDs. This tool addresses issues where bundling CRDs with Helm charts or other
  add-ons can lead to conflicts, downgrades, or unintended channel switching.

Key Features:
   * Safe Upgrades: Automatically upgrades CRDs to a target version only if the new version is strictly newer than the installed version.
   * Standard Channel Enforcement: Strictly enforces the standard release channel. Operations targeting experimental channels are blocked to prevent stability regressions.
   * Conflict Prevention: Detects and skips upgrades if a channel mismatch is found (e.g., attempting to upgrade a standard CRD with an experimental manifest).
   * Flexible Modes: Supports listing installed CRDs, upgrading all existing CRDs, or targeting a specific subset of CRDs for installation.

Usage: Users can build the provided Docker image and deploy the appropriate Job manifest (job-all.yaml, job-subset.yaml, or job-list.yaml) to perform the desired operation. See README.md for detailed instructions.

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