[WIP] Refactor logging

[hanlint]

This PR refactors the logging to:

• centralize verbosity controls into the python logging levels, instead of passing verbose arguments to many helper methods
• downgrades most warnings to info level. warnings should only be used for errors or unexpected behavior that do not require raising an exceptions, not informative messages such as reporting expected behavior.
• removes the warnings around usage of torch vs. triton vs. flash. These have led to users mistakenly believing this is the source of other errors.

Note: This PR is API-breaking. Should I keep the verbose arguments to the methods, and add a deprecation warnings instead that this argument is being ignored?

TODO:

• [ ] add python log level control in scripts
• [ ] move the attention implementation information to an FAQ
• [ ] add some protection for invalid choices (e.g. alibi and attn_impl conflicts)
• [ ] remove remaining verbose and warnings