Allow voice message playback in the background

[stefanceriu]

• inform other audio sessions on deactivation
• let CallKit handle the audioSession for ElementCall
• add support for showing media playback controls on the lock screen (mostly copied from my original Riot implementation here

[github-actions]

	Warnings
⚠️	Some of the commits are missing ticket numbers. Please consider squashing all commits that don't have a tracking number.
⚠️	You seem to have made changes to views. Please consider adding screenshots.

Generated by 🚫 Danger Swift against d245956

[codecov]

Codecov Report

Attention: Patch coverage is 20.16807% with 95 lines in your changes missing coverage. Please review.

Project coverage is 45.08%. Comparing base (0f3b33c) to head (d245956).
Report is 9 commits behind head on develop.

Files with missing lines	Patch %	Lines
...urces/Services/Audio/Player/AudioPlayerState.swift	5.71%	66 Missing ⚠️
...tX/Sources/Services/Audio/Player/AudioPlayer.swift	0.00%	10 Missing ⚠️
.../Timeline/TimelineItems/RoomTimelineItemView.swift	0.00%	3 Missing ⚠️
UnitTests/Sources/AudioPlayerStateTests.swift	0.00%	3 Missing ⚠️
...tTests/Sources/ComposerToolbarViewModelTests.swift	0.00%	3 Missing ⚠️
UnitTests/Sources/MediaPlayerProviderTests.swift	0.00%	3 Missing ⚠️
...s/FlowCoordinators/OnboardingFlowCoordinator.swift	0.00%	1 Missing ⚠️
...X/Sources/Screens/CallScreen/View/CallScreen.swift	0.00%	1 Missing ⚠️
...omposerToolbar/View/MessageComposerTextField.swift	75.00%	1 Missing ⚠️
.../Screens/Timeline/TimelineInteractionHandler.swift	0.00%	1 Missing ⚠️
... and 3 more

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3236      +/-   ##
===========================================
- Coverage    45.11%   45.08%   -0.04%     
===========================================
  Files          722      722              
  Lines        53901    53963      +62     
===========================================
+ Hits         24320    24330      +10     
- Misses       29581    29633      +52     

Flag	Coverage Δ
unittests	35.56% <20.16%> (-0.03%)	⬇️

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[github-actions]

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[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[CLAassistant]

All committers have signed the CLA.

[CLAassistant]

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[pixlwave]

Nice!