Fix: representation returned by public API has incorrect shape

[Florent-Bouisset]

The methods getVideoRepresentation and getAudioRepresentation returns object that are not matching the shape described in the documentation.
The issue is also present on events payload for events videoRepresentationChange and audioRepresentationChange.

[github-actions]

? Automated performance checks have passed on commit 251b6e256d9fefb5d44e37f09262cf81159efae8 with the base branch dev.

Details

Performance tests 1st run output

No significative change in performance for tests:

Name	Mean	Median
loading	19.61ms -> 19.98ms (-0.366ms, z: 0.61574)	27.15ms -> 27.15ms
seeking	15.74ms -> 17.10ms (-1.362ms, z: 0.37962)	10.95ms -> 10.95ms
audio-track-reload	25.88ms -> 25.98ms (-0.103ms, z: 1.35007)	37.80ms -> 37.85ms
cold loading multithread	46.12ms -> 45.55ms (0.577ms, z: 13.55417)	67.95ms -> 66.90ms
seeking multithread	41.01ms -> 38.40ms (2.604ms, z: 0.34383)	10.05ms -> 10.05ms
audio-track-reload multithread	25.59ms -> 25.68ms (-0.091ms, z: 0.88034)	37.65ms -> 37.80ms
hot loading multithread	14.98ms -> 14.84ms (0.144ms, z: 4.95290)	21.75ms -> 21.60ms

[peaBerberian]

LGTM