feat: add dump_stats to advanced profiler (#19698)

[clumsy]

What does this PR do?

Adding a new dump_stats flag to AdvanedProfiler to persist .prof files collected during profiling. These files can be visualized by SnakeViz like so: snakeviz fit-run-[Strategy]DDPStrategy.on_train_end.prof

A .prof file is created for each profiled action, e.g.:

...
fit-run-[Strategy]DDPStrategy.on_train_end.prof
fit-run-[Callback]TQDMProgressBar.on_fit_end.prof
fit-run-[Callback]ModelSummary.on_fit_end.prof
fit-run-[Callback]ModelCheckpoint{'monitor': None, 'mode': 'min', 'every_n_train_steps': 0, 'every_n_epochs': 1, 'train_time_interval': None}.on_fit_end.prof
fit-run-[Callback]LearningRateMonitor.on_fit_end.prof
...

Fixes #19698

No breaking changes, adding a new backward-compatible flag, with the new functionality disabled by default.

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📚 Documentation preview 📚: https://pytorch-lightning--19703.org.readthedocs.build/en/19703/

[clumsy]

For your consideration, @awaelchli

[clumsy]

Are there any concerns about this change, @awaelchli? Thanks!