Add MuP optimizers (#2043)
* added paths for mup optimizers
* added tests
* formatting
* Add license, fix missing distributed test, formatting
* Add mpi4py to confirm tests work
* Undo requirements change
* Move to runtime folder
* Rework to match new format
* missing comma
* hidden dim fix
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Co-authored-by: Logan Adams <114770087+loadams@users.noreply.github.com>
Co-authored-by: Logan Adams <loadams@microsoft.com>
