Add parallel attachment uploading

[nuno-vieira]

🔗 Issue Links

Resolves https://github.com/GetStream/ios-issues-tracking/issues/701

🎯 Goal

Adds parallel attachment uploading

📝 Summary

• Fix back button in Demo App's message list
• Add parallel attachment uploading

🛠 Implementation

Before, we were uploading the next attachment only when the current attachment finished uploading. This is not needed at all. We can start all uploads at the same time.

🎨 Showcase

Simulator.Screen.Recording.-.iPhone.14.Pro.-.2024-02-16.at.18.30.34.mp4

🧪 Manual Testing Notes

Scenario 1

1. Open a channel
2. Add a message with multiple attachments
3. All attachments should start uploading at the same time

Scenario 2

1. Open a channel
2. Add a message with multiple attachments
3. Add another message with multiple attachments
4. Both messages's attachments should uploading at the same time

☑️ Contributor Checklist

• I have signed the Stream CLA (required)
• This change follows zero ⚠️ policy (required)
• This change should be manually QAed
• Changelog is updated with client-facing changes
• New code is covered by unit tests
• Comparison screenshots added for visual changes
• Affected documentation updated (docusaurus, tutorial, CMS)

[sonarcloud]

Quality Gate passed

Issues
45 New issues

Measures
0 Security Hotspots
91.5% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[laevandus]

Alternative could be pendingAttachmentIDs.formUnion(newAttachmentIds). But it does not matter much.

[laevandus]

@nuno-vieira The flickering in the gallery view is going to be taken care by a separate issue?

[martinmitrevski]

This is a great improvement 👏 I also tested on SwiftUI, it works well there too.
Do we have a follow up about/ideas to fix the flickering?

[nuno-vieira]

@laevandus @martinmitrevski The flickering requires rebuilding the Gallery View, unfortunately, so we would need a new GalleryViewInjector implementation.