terraform: add missing policies for AWS ALB

[burgerdev]

Context

Node role permissions are currently handcrafted to allow the set of use cases we identified so far. We did not consider the use of AWS LBC as an Ingress provisioner, though, and thus never checked whether the policies are sufficient.

Proposed change(s)

• Apply the recommended policy.
• Add a test to ensure ALB Ingresses can be created.
• Document considerations for using ALB Ingress with Constellation.

Related issue

• Fixes #3056

Checklist

• [x] Run the E2E tests that are relevant to this PR's changes
  • https://github.com/edgelesssys/constellation/actions/runs/8938280204/job/24552109686 (intermediate state)
  • https://github.com/edgelesssys/constellation/actions/runs/8968562872 (current HEAD)
• [x] Update docs
• [x] Add labels (e.g., for changelog category)
• [x] Is PR title adequate for changelog?
• [x] Link to Milestone

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