Fetch and render cluster sync badges on environment page

What does this MR do and why?

This MR adds a Flux sync status. Here're the possible statuses:

Status	Conditions	Badge
Failed	at least one { type: Ready, status: "False" }
Stalled	no failed, at least one { type: Stalled, status: "True" }
Reconciling	no failed, no stalled, at least one { type: Reconciling, status: "True" }
Reconciled	no failed, no stalled, no reconciling, at least one { type: Ready, status: "True" }
Unknown	other combinations
Unavailable	no Kustomizations or HelmReleases found

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Status	Screenshot
Reconciled
Reconciling
Failed

How to set up and validate locally

1. Enable feature flags:

      Feature.enable(:kubernetes_namespace_for_environment)

2. Enable KAS on your GDK (steps 1-2 from the guide).

3. Visit the Project -> Infrastructure -> Kubernetes clusters page and create an agent following the instruction from the modal.

   • Select the "Connect a cluster" button
   • The modal should pop up
   • In the modal select "Select an agent or enter a name to create new"
   • You probably won't have any configured agents to show up in the list, create a new one by typing the name of your choice
   • The button should appear at the bottom of the list saying "Create agent: <your-agent-name>"
   • Select the button and click "Register" in the next view.
   • Save the token to use it in the next point.

4. Please follow points 3-8 from the guide and then the (Optional) Deploy the GitLab Agent (agentk) with k3d section to create a local cluster and connect your agent with the cluster.

5. Add the following configuration for your agent, commit the following on the default branch: .gitlab/agents/<your-agent-name>/config.yaml:

   gitops:
     manifest_projects:
     - id: <your-group>/<your-project>
   user_access:
     access_as: 
       agent: {}
     projects:
     - id: <your-group>/<your-project>

6. Follow this guide to start with the Flux

7. Visit the Environments page:

   • Project -> Operate -> Environments if the new navigation is enabled
   • Project -> Deployments -> Environments if the new navigation is not enabled

8. Create/Edit an environment using the UI, select the agent created in the previous steps and the namespace used for the Flux setup (usually, called flux-system)

9. Navigate to the Environments page, toggle the environment, wait for the Kubernetes overview to appear, and verify the Flux sync label

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Review progress:

• UX review
• frontend developer review
• frontend maintainer review

Related to #391581 (closed)