fix(nms): Only show policy placeholder if all tabs are empty

[thmsschmitt]

Summary

Show the Policy placeholder only if all tabs on the policy page are empty.

• Fixes: [NMS] Policy placeholder is not removed when creating base names, profiles or rating groups  #13257

Test Plan

Follow the steps to reproduce in #13257. Make sure that the placeholder is only shown if nothing has been created.
Also verify that the placeholder reappears if all policy tabs become empty.

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[github-actions]

dp-workflow

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Results for commit 0d6df93.

[github-actions]

nms-workflow

0 tests   0 ✔️  0s ⏱️
0 suites  0 💤
0 files    0 ❌

Results for commit 0d6df93.