Fix fabric examples and load_checkpoint hparams ref

[SkafteNicki]

What does this PR do?

Fixes #20303
Fix single location in documentation where model.learning_rate is reference after loading a checkpoint. Should instead be model.hparams.learning_rate.

and...

Fixes #20622
The specific problems mentioned in this issue are already resolved in another PR, however similar problems could be found in two example scripts. Namely that the order of arguments to fabric.save was switched. Solved this.

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📚 Documentation preview 📚: https://pytorch-lightning--21013.org.readthedocs.build/en/21013/