Fix issues (IR, layout, Rule{:id})

[ChenZhao44]

1. Fix the case that full_reduction will create IRs that cannot be converted to ZXDiagrams.
2. Makes generate_layout more general.
3. Makes Rule{:id} capable with inner Z-spiders (fix id rule for inner spiders for ZXGraph #78 ).

[codecov]

Codecov Report

Merging #86 (1d91bac) into master (46532b1) will decrease coverage by 0.51%.
The diff coverage is 70.65%.

@@            Coverage Diff             @@
##           master      #86      +/-   ##
==========================================
- Coverage   93.76%   93.25%   -0.52%     
==========================================
  Files          11       11              
  Lines        1749     1927     +178     
==========================================
+ Hits         1640     1797     +157     
- Misses        109      130      +21     

Impacted Files	Coverage Δ
src/rules.jl	91.60% <45.65%> (-3.01%)	⬇️
src/zx_graph.jl	93.60% <92.85%> (-1.61%)	⬇️
src/ir.jl	89.24% <100.00%> (+1.24%)	⬆️
src/simplify.jl	94.66% <100.00%> (+7.06%)	⬆️
src/zx_diagram.jl	96.78% <100.00%> (-0.06%)	⬇️
src/scalar.jl	100.00% <0.00%> (ø)
src/phase_teleportation.jl	100.00% <0.00%> (ø)
... and 4 more

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