Refactor media loading

[StaehliJ]

Pull request

Description

The goal of this PR is to improve customizability when loading content with Pillarbox. This PR make also more clear where trackers data can be set or not. AssetLoader replace MediaItemSource, integrators have more control of how creating MediaSource, setting up MediaMetadata and trackers data.

Loading SRG content

val mediaItem = SRGMediaItemBuilder(urn).build()
pillarboxPlayer.addItem(mediaItem)

Loading Non SRG content

val mediaItem = MediaItem.fromUri(mediaUri).build()
pillarboxPlayer.addItem(mediaItem)

Custom content

For custom content, there is only one rule, MediaItem.Builder.setUri have to be called.

For example it could be:

val mediaItem = MediaItem.Builder()
    .setUri("custom:id:1234")
    .setMediaId("1234")
.build()
pillarboxPlayer.addItem(mediaItem)

Changes made

• Remove MediaItemSource replaced by AssetLoader.
• Tracker data can't be updated during playback.
• MediaItem.tag is removed when passed to PillarboxPlayer as it is use for internally by trackers.

Checklist

• Your branch has been rebased onto the main branch.
• APIs have been properly documented (if relevant).
• The documentation has been updated (if relevant).
• New unit tests have been written (if relevant).
• The demo has been updated (if relevant).
• All pull request status checks pass.

[github-actions]

Code Coverage

Overall Project	55.25% -1.18%	🟢
Files changed	90.63%	🟢

Module	Coverage
:pillarbox-core-business	84.74% -1.91%	🟢
:pillarbox-player	73.15% -1.99%	🟢

Files

Module	File	Coverage
:pillarbox-core-business	HttpMediaCompositionService.kt	100%	🟢
	SRGEventLoggerTracker.kt	100%	🟢
	MediaUrn.kt	100%	🟢
	ImageScalingService.kt	100%	🟢
	ResourceSelector.kt	100%	🟢
	AkamaiTokenDataSource.kt	100%	🟢
	DefaultMediaMetaDataProvider.kt	98.84% -1.16%	🟢
	SRGMediaItemBuilder.kt	97.78% -2.22%	🟢
	CommandersActTracker.kt	97.1%	🟢
	SRGAssetLoader.kt	87.04% -12.96%	🟢
	ComScoreTracker.kt	81.31%	🟢
	DefaultPillarbox.kt	57.84% -8.82%	🟢
:pillarbox-player	AssetLoader.kt	100%	🟢
	Asset.kt	100%	🟢
	MediaItemTracker.kt	100%	🟢
	CurrentMediaItemTracker.kt	95.51% -2.47%	🟢
	MediaItemTrackerData.kt	94.26%	🟢
	UrlAssetLoader.kt	92.41% -7.59%	🟢
	PillarboxMediaSource.kt	90.94% -0.67%	🟢
	PillarboxPlayer.kt	68.89% -0.83%	🟢
	PillarboxMediaSourceFactory.kt	53.46% -46.54%	🟢

[MGaetan89]

I've pushed some documentation/naming changes, otherwise, it looks good 👍🏻