Feature: #103441 - Request ID as public visible error reference in error handlers output

See forge#103441

Description

The ProductionExceptionHandler in EXT:core outputs error details, but not for everyone. As a normal visitor you don't see any traceable error information.

The ProductionExceptionHandler in EXT:frontend outputs "Oops, an error occurred!" followed by a timestamp and a hash. This is part of log messages.

Whenever an error/exception is logged, the log message contains the request ID.

With this the request ID is also shown in web output of error/exception handlers
as public visible error reference.

Impact

Everyone sees a request id as traceable error information.