[plugin-web-app-playwright] Add validation of elements state step

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 97.48%. Comparing base (b6b78cd) to head (346cbf9).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #5214 +/- ## ========================================= Coverage 97.47% 97.48% - Complexity 6835 6857 +22 ========================================= Files 944 947 +3 Lines 19754 19815 +61 Branches 1306 1309 +3 ========================================= + Hits 19255 19316 +61 Misses 390 390 Partials 109 109 ```

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