Update on "[et][dim order] Makes DimOrderOpsMap as an operator to operator mapping"

This diff updates DimOrderOpsMap from name-to-operator mapping to operator-to-operator mapping, which has multiple benefits:

1. Reduce dialect ambiguity. Different dialects op may map to same name (e.g. `aten.to_copy` and `exir_ops.edge.aten._to_copy.default`). Directly using op can diminish the ambiguity.
2. Auto-maintain MemoryFormatOpsMap by reverting DimOrderOpsMap

Differential Revision: [D66773612](https://our.internmc.facebook.com/intern/diff/D66773612/)

[ghstack-poisoned]

Author: Gasoonjia

exir/passes/dim_order_ops_registry.py

@@ -58,14 +58,14 @@ def _empty_dim_order_out_impl(*args, **kwargs):
 
 
 """
-Defines a map of aten or edge ops to the corresponding dim_order ops for quick lookup
+Defines a map of edge ops to the corresponding dim_order ops for quick lookup
 """
 DimOrderOpsMap = {
     exir_ops.edge.aten._to_copy.default: exir_ops.edge.dim_order_ops._to_dim_order_copy.default,
     exir_ops.edge.aten.empty.memory_format: exir_ops.edge.dim_order_ops._empty_dim_order.default,
 }
 
 """
-Defines a map of aten or edge ops to the corresponding memory format ops for quick lookup, which is the revert of DimOrderOpsMap
+Defines a map of edge ops to the corresponding memory format ops for quick lookup, which is the revert of DimOrderOpsMap
 """
 MemoryFormatOpsMap = {v: k for k, v in DimOrderOpsMap.items()}