[SPARK-17769][CORE][SCHEDULER] Some FetchFailure refactoring

## What changes were proposed in this pull request?

Readability rewrites.
Changed order of `failedStage.failedOnFetchAndShouldAbort(task.stageAttemptId)` and `disallowStageRetryForTest` evaluation.
Stage resubmission guard condition changed from `failedStages.isEmpty` to `!failedStages.contains(failedStage)`
Log all resubmission of stages
## How was this patch tested?

existing tests

Author: Mark Hamstra <markhamstra@gmail.com>

Closes #15335 from markhamstra/SPARK-17769.