refactor: Flatten Flow Control inter-flow policy plugin directory structure

[LukeAVanDrie]

What type of PR is this?

/kind cleanup

What this PR does / why we need it:

This PR flattens the directory structure for InterFlowDispatchPolicy plugin implementations within pkg/epp/flowcontrol/framework/plugins/policies/interflow/dispatch/.... Specifically, it moves everything directly into a new pkg/epp/flowcontrol/framework/plugins/interflow package, removing the need for separate subdirectories and two redundant layers of nesting. This simplifies import paths and the overall project layout.

This is a no-op refactoring to improve code organization.

Which issue(s) this PR fixes:

Tracks #1794

Does this PR introduce a user-facing change?:

NONE

[netlify]

✅ Deploy Preview for gateway-api-inference-extension ready!

Name	Link
🔨 Latest commit	87c188f
🔍 Latest deploy log	https://app.netlify.com/projects/gateway-api-inference-extension/deploys/6924d1c51fac5200089f7612
😎 Deploy Preview	https://deploy-preview-1841--gateway-api-inference-extension.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[k8s-ci-robot]

Hi @LukeAVanDrie. Thanks for your PR.

I'm waiting for a github.com member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[kfswain]

/ok-to-test

[kfswain]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: kfswain, LukeAVanDrie

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• OWNERS [kfswain]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment