Migrate fly_out_nav spec to Jest

What does this MR do?

Migrate fly_out_nav_browser_spec.js to Jest. Since the original test relies on browser rendering this test was ported as an integration test. In addition, Karma runs this test in a real browser but this test depends on the getBoundingClientRect API which is not available in JSDom (it's available actually but it returns zero for all values) I took the following approach for the migration:

1. I ran all tests in Karma and made notes where it calls getBoundingClientRect with values.
2. I removed all redundant values from these calls
3. I used these values to mock values in JSDom. So basically in current tests we mock initial values after the HTML was set and processed.

I decided to keep the original test for some time so I added comments where I mocked values.

Closes #281811 (closed)

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Does this MR meet the acceptance criteria?

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