feat: polls implementation

[isekovanic]

🎯 Goal

This PR adds support for Polls within the SDK. It goes paired with this one in the LLC.

It includes:

• The Poll component (essentially Poll message)
• All of the various screens the Poll exposes (results, answers, full option votes, poll creation and the dialogs)
• We allow customizability and the exposure of our own components (that work OOTB through using the default hooks) for the Poll component in separate segments; its header, options and then the buttons section
• Each button can have its onPress handler overriden which allows for customizability whenever this happens
• If the onPress handler is overriden, both poll and message are passed so that the PollContext can be reconstructed on each screen
• Each screen comes with its own mechanism to reconstruct its top level context and requires poll and message specifically
• Various utility hooks that can be used to consume the poll state for convenience

TODO:

• Clean up some parts of the code (specifically component overrides)
• Double check that theming is working well
• If there is time, maybe try to make the animation logic on the poll creation screen at least a bit customizable
• Use capabilities

🛠 Implementation details

🎨 UI Changes

iOS

Before	After

Android

Before	After

🧪 Testing

☑️ Checklist

• I have signed the Stream CLA (required)
• PR targets the develop branch
• Documentation is updated
• New code is tested in main example apps, including all possible scenarios
  • SampleApp iOS and Android
  • Expo iOS and Android

[stream-ci-bot]

🎉 This PR is included in version 5.40.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀