[ENH] Add Moirai-MoE foundation model to v2 interface

[priyanshuharshbodhi1]

Proposing to add Salesforce Moirai-MoE as a v2 forecaster, interfacing the uni2ts package as a soft dependency. Tracked under the v2 wishlist in #1992.

I have already worked on adding Moe and Moirai-2.0 models in sktime. sktime/sktime#9544