refactor(demo-playwright): use DemoRoute inside playwright tests

[nsbarsukov]

Relates to:

• 📚 - Replace all hard-coded documentation relative links with DemoRoute #7186

[lumberjack-bot]

Pull request was closed ✔️

All saved screenshots (for current PR) were deleted 🗑️

[bundlemon]

BundleMon

Unchanged files (5)

Status	Path	Size	Limits
✅	demo/browser/main.(hash).js	297.11KB	+10%
✅	demo/browser/vendor.(hash).js	243KB	+10%
✅	demo/browser/runtime.(hash).js	41.1KB	+10%
✅	demo/browser/styles.(hash).css	13.75KB	+10%
✅	demo/browser/polyfills.(hash).js	11.21KB	+10%

No change in files bundle size

Unchanged groups (1)

Status	Path	Size	Limits
✅	demo/browser/*..js	7.34MB	-

Final result: ✅

View report in BundleMon website ➡️

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Current branch size history | Target branch size history

[github-actions]

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