Tile channels for group norm and also fuse output reshapes in mlir

[pfultz2]

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3750      +/-   ##
===========================================
+ Coverage    92.16%   92.81%   +0.65%     
===========================================
  Files          515      520       +5     
  Lines        21978    23736    +1758     
===========================================
+ Hits         20256    22030    +1774     
+ Misses        1722     1706      -16     

see 29 files with indirect coverage changes

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