Move CheckpointConnector.fault_tolerant_auto_save_path out of CheckpointConnector.hpc_resume_path

[jjenniferdai]

What does this PR do?

Item 1. in #9407 (comment)
Part of #9407 cleanup, move CheckpointConnector.fault_tolerant_auto_save_path out of CheckpointConnector.hpc_resume_path.

Note that unless we change line 165 here to if self.hpc_resume_path or self.fault_tolerant_auto_save_path is not None: , this means fault-tolerant checkpoints will no longer run on_hpc_load hook (deprecated but not yet removed).
I think this is the correct behavior, though lmk if you think line 165 should be edited to preserve the same behavior as before.
https://github.com/PyTorchLightning/pytorch-lightning/blob/3c4d06bd42ff3282a017cd9fa879bbd68e8568df/pytorch_lightning/trainer/connectors/checkpoint_connector.py#L163-L166

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