chore: persist warnings per preview app's version when comparing plugins from preview app with local plugins

[Fatme]

In case when QR code is scanned with 2 different devices with the same version of preview app, {N} CLI will compares 2 times plugins from preview app with local plugins.

PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
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• All existing tests are passing: https://github.com/NativeScript/nativescript-cli/blob/master/CONTRIBUTING.md#contribute-to-the-code-base
• Tests for the changes are included.

What is the current behavior?

{N} CLI compares 2 times plugins from preview app with local plugins when QR code is scanned with 2 different devices with the same version of preview app.

What is the new behavior?

{N} CLI compares only once plugins from preview app with local plugins when QR code is scanned with 2 different devices with the same version of preview app.