Fix repeated segments issue during bandwidth update

[dzianis-dashkevich]

Description

We may encounter duplicate segment loading during bandwidth updates.
Since we are re-calculating timestampOffset during each quality switch it results in presenting of duplicate segments.

Consider the following situation:

This log is placed in the chooseNextRequest_.
As you can see:

• The player selected MediaSequence 28 from playlist A.
• Then, the player switched quality to playlist B because of the bandwidth update.
• Then, the player selected MediaSequence 28 despite the fact that it was already buffered from the previous playlist.
• This happens because of the slight difference between the buffered.end and the sum of durations from the playlist.

Specific Changes proposed

Make an assumption that some segment or segment's part is already buffered if the difference between segment.end and buffered.end is less or equal to 2 * TIME_FUDGE_FACTOR (which is 0.06)
Fallback by selecting the next part or segment using buffered.end + difference padding.

Requirements Checklist

• Feature implemented / Bug fixed
• If necessary, more likely in a feature request than a bug fix
  • Unit Tests updated or fixed
  • Docs/guides updated
  • Example created (starter template on JSBin)
• Reviewed by Two Core Contributors

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (5b87f69) 86.06% compared to head (3d04436) 87.13%.
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1477      +/-   ##
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+ Coverage   86.06%   87.13%   +1.07%     
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  Files          42       42              
  Lines       10748    11887    +1139     
  Branches     2474     2904     +430     
==========================================
+ Hits         9250    10358    +1108     
- Misses       1498     1529      +31     

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[wseymour15]

Approved after nit comments are addressed.

[adrums86]

LGTM. I do think it's probably worth adding a quick test or 2 for the <= extendedFudgeFactor and !mediaInfo cases however.

[adrums86]

!