Added an error condition

Added tests for the spare field

Minor change in the documentation

Reimplement the spare field

Updated ErrorType enums in ExecutionStartErrorType and changed the corresponding errors in EventActionService.cpp

Wrote better tests, fixed code format, added tests in main for testing purposes and added FailedStartOfExecutionError in ErrorHandler

Closes #14
Closes #8

Configure the step identifier for the reports about the progress of the execution of a request. The ErrorHandler has been updated