Fix cyclic handling and resolve bug #63206 in error and exception han…

[pavelzotikov]

This PR addresses several key improvements in the error and exception handling flow, specifically resolving cyclic error handling issues and fixing bug #63206. The following changes have been made:

1. Cyclic Error Prevention: The logic has been updated to prevent infinite loops by ensuring that an exception previously handled by a custom handler is properly delegated back to the native PHP handler if it matches the current exception.
2. Bug #63206: A fix for bug #63206 was implemented, which caused issues with error reporting duplication and cyclic behavior in the error handling process.
3. Fatal Error Handler Disablement: Adjusted the fatal error handler to prevent errors from being reported twice in cases of shutdown errors.
4. Improved Context Handling: Refined the context merging logic to ensure all event data is properly processed before sending.

These improvements enhance the robustness of the SDK, preventing redundant error reporting and ensuring proper exception handling flow.