Added a few functions for simple constants (eg, x + 1, 1/x, etc). Th…

[neonWhiteout]

…eir definitions are seen in visualization. Dyvars can now have arbitrarily many operators, similar to flow dyvars.

[codecov[bot]]

Codecov Report

Attention: 47 lines in your changes are missing coverage. Please review.

Comparison is base (e5eec69) 57.98% compared to head (e795d00) 57.12%.

Files	Patch %	Lines
src/visualization.jl	0.00%	22 Missing :warning:
src/Syntax.jl	56.81%	19 Missing :warning:
src/StockFlow.jl	0.00%	6 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #107      +/-   ##
==========================================
- Coverage   57.98%   57.12%   -0.86%     
==========================================
  Files          10       10              
  Lines        2016     2076      +60     
==========================================
+ Hits         1169     1186      +17     
- Misses        847      890      +43     

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[neonWhiteout]

I guess one thing to note is, when generating names for the new dynamic variables, it always prepends the previous, which can lead to some nesting like ##v_##v_v#1498#1499.