Revisit exception declaration in public APIs

[fmbenhassine]

As of v5.2, several public APIs declare exceptions that are not thrown, or thrown at the wrong level of abstraction. Here are a few examples:

• JobRestartException is currently defined in the data access layer (ie the org.springframework.batch.core.repository package where it is thrown by JobRepository#createJobExecution) while it should be at the job operator level (thrown by JobOperator#restart(JobExecution jobExecution))
• JobOperator#start(Job job, JobParameters jobParameters) throws a NoSuchJobException even if the job is passed as a parameter (ie it is not just an id that should be fetched from the registry and which might result in a NoSuchJobException if the job is not recognised)
• JobOperator#restart(JobExecution jobExecution) throws a NoSuchJobExecutionException even if the exception is passed as a parameter (similar to the previous point)
• org.springframework.batch.item.file.transform.ConversionException is not used
• org.springframework.batch.item.validator.ValidationException currently extends ItemReaderException but it is not related to item reading, it is used by the item processor when validating items

This should be reviewed in v6