Refactored multiple items

[berghtho]

Summary

Improves error handling and functional composition across FunctionalUseCases.

Changes

• Preserve original exceptions and stack traces in ExecutionError.Exception
• Throw ExecutionException from failed CheckedValue
• Set original exception as ExecutionException.InnerException
• Pass preserved exceptions to ILogger
• Add Match, Map, Bind, and GetValueOrThrow
• Support string error codes and structured error properties
• Replace reflective dispatcher invocation with cached strongly typed invokers
• Preserve error metadata when mapping, binding, or combining results
• Add optional FunctionalUseCases.AspNetCore package
• Add IActionResult and ProblemDetails mappings
• Correct README/API mismatches

Breaking Changes

ExecutionError.ErrorCode

Changed from:

int? ErrorCode