fix websocket and restore describeview

[saipreetham16]

Description:

Summary

This PR restores the previously reverted DescribeView feature and fixes the WebSocket crash caused by force-unwrapping
optional JSON fields in WebSocket message handlers.

Background

The DescribeView feature (PR #96) was reverted in PR #98 due to a reported crash (JSONException: No value for MessageId).
Investigation confirmed that:

• The crash is in WebSocketManager.handleMetadata() — a pre-existing bug unrelated to DescribeView
• The DescribeView commit never modified WebSocketManager.kt
• The crash occurs when interactive messages include MessageMetadata without a MessageId field, and the SDK uses
  getString() (which throws) instead of optString() (which returns a default)

Changes

1. Restore DescribeView API support

• Re-reverts commit a8fd788 to restore describeView() across ChatSession, ChatService, and AWSClient
• Adds ViewResourceContent model for ShowView block interactive messages
• Adds View / ViewContent data models
• Adds ViewContentView composable in example app

2. Fix: Loosen message property requirements in WebSocket handler

• Replaces all getString() and getJSONObject() calls with optString() / optJSONObject() in WebSocketManager.kt
• Affected methods: handleMessage, handleParticipantEvent, handleTyping, handleChatEnded, handleMetadata, handleAttachment
• Missing fields gracefully default to empty strings instead of crashing

3. Version bump to 2.0.11

Testing

• Unit tests: 23 new tests covering all handler methods with complete fields, missing fields, and edge cases (187
  total, 0 failures)
• Example app — DescribeView: Verified with ShowView block flow — describeView() successfully fetches view schema
• Example app — Interactive messages: Verified LIST PICKER and TIME PICKER flows work without crashes
• Crash reproduction: Confirmed crash reproduces by stripping MessageId from WebSocket payloads, and confirmed fix
  resolves it