Bt 5584/check for comodification

[BartoszLitwiniuk]

Summary

This PR fixes a potential ConcurrentModificationException in BacktraceDatabaseContext, which could occur during deletion operations in the BacktraceHandlerThread when context is used by multiple threads.

Key Changes

• Replaced List with thread-safe collection types where necessary to ensure safe concurrent access.
• Refactored internal logic to avoid mutating collections during iteration.
• Added safeguards and checks to prevent runtime exceptions during batch operations.

Impact

• Prevents crashes caused by concurrent modifications during database record handling.
• Enhances the robustness and reliability of the SDK in multithreaded environments.