Fix reshape

[benedict-96]

Fixes #19
Fixes #18
Introduces a keyword argument reduce that specifies which operation should be used to perform mapreduce in build_nn_function (and similar functions).

But introduces type pyracy! Maybe Fixes #18 should be fixed by doing a pr in SymbolicUtils.

[codecov]

Codecov Report

Attention: Patch coverage is 90.00000% with 3 lines in your changes missing coverage. Please review.

Project coverage is 77.32%. Comparing base (5343bae) to head (81c7135).
Report is 10 commits behind head on main.

Files with missing lines	Patch %	Lines
src/build_function/build_function_double_input.jl	72.72%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #20      +/-   ##
==========================================
+ Coverage   74.21%   77.32%   +3.10%     
==========================================
  Files          11       12       +1     
  Lines         256      269      +13     
==========================================
+ Hits          190      208      +18     
+ Misses         66       61       -5     

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[benedict-96]

NOTE: This pr is set to "draft" until JuliaSymbolics/SymbolicUtils.jl#644 is fixed.

[benedict-96]

The issue mentioned above JuliaSymbolics/SymbolicUtils.jl#644 still hasn't been fixed since JuliaSymbolics/SymbolicUtils.jl#679 has not been merged. I will solve that problem for now by introducing the slight type piracy via:

function Symbolics.SymbolicUtils.Code.create_array(::Type{<:Base.ReshapedArray{T, N, P}}, S, nd::Val, d::Val, elems...) where {T, N, P}
    Symbolics.SymbolicUtils.Code.create_array(P, S, nd, d, elems...)
end