EGraph pattern matcher when instantiating substitutions only instantiates symbols as term operations

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EGraph pattern matcher when instantiating substitutions only instantiates symbols as term operations even if the original e-node that is being rewritten has a function object as its operation. This problem gets in the way for the SymbolicUtils.jl integration.
Here's an example (just figurative. not working, needs some expression preprocessing tweaks)

using SymbolicUtils
using Metatheory

@syms a b 
ex = a + b
t = [@rule x y x + y => x * y]
g = EGraph(ex)
saturate!(g, t) # FAILS because it's creating Term{...}(:*, eclass_of_x, eclass_of_y) instead of using the actual (*) function object