Feat/patchtst fm

[spolisar]

Add support for the new PatchTST-FM forecasting model.

PatchTST-FM is currently setup to use pytorch's mps backend when available, but there is a chance that will have issues. If it becomes a problem, we can disable that.

TODO:

• Determine notebook position in example list

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}