Add support for W-spiders, differentiation, and integration

[ChenZhao44]

The PR add supports for #16 and #76

[codecov]

Codecov Report

Merging #91 (1b71b43) into master (bbc19ab) will decrease coverage by 5.12%.
The diff coverage is 63.67%.

@@            Coverage Diff             @@
##           master      #91      +/-   ##
==========================================
- Coverage   94.34%   89.21%   -5.13%     
==========================================
  Files          11       15       +4     
  Lines        2085     2337     +252     
==========================================
+ Hits         1967     2085     +118     
- Misses        118      252     +134     

Impacted Files	Coverage Δ
src/plots/zx_plot.jl	0.00% <0.00%> (ø)
src/plots/zx_plot_compose.jl	0.00% <0.00%> (ø)
src/plots/zx_plot_vega.jl	0.00% <0.00%> (ø)
src/simplify.jl	94.66% <ø> (-0.08%)	⬇️
src/ir.jl	84.79% <72.72%> (-6.98%)	⬇️
src/zx_diagram.jl	96.50% <84.61%> (-0.35%)	⬇️
src/phases/pi_unit.jl	89.33% <89.33%> (ø)
src/zx_graph.jl	93.60% <91.66%> (+0.38%)	⬆️
src/omeinsum/to_eincode.jl	97.75% <97.75%> (ø)
src/circuit_extraction.jl	96.04% <100.00%> (+0.28%)	⬆️
... and 6 more

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[ChenZhao44]

I closed this PR because @exAClior has been working on this project.