feat: Allow Conditions to be used in isolation

[iph]

Apparently conditions can just be "another condition". Weird use case, but I've found some templates that have this. Added Condition as the highest level to allow those templates to work.

[codecov]

Codecov Report

Merging #151 (2b5a7e2) into main (fff7f0d) will increase coverage by 0.4%.
The diff coverage is 88.9%.

Additional details and impacted files

Components	Coverage Δ
Parser	77.1% <81.8%> (+2.0%)	⬆️
Intermediate Representation	81.8% <100.0%> (+0.1%)	⬆️
Synthesizers	87.6% <100.0%> (+<0.1%)	⬆️
Other	49.7% <ø> (ø)

@@           Coverage Diff           @@
##            main    #151     +/-   ##
=======================================
+ Coverage   81.5%   81.9%   +0.4%     
=======================================
  Files         24      24             
  Lines       2743    2758     +15     
  Branches    2743    2758     +15     
=======================================
+ Hits        2236    2258     +22     
+ Misses       342     334      -8     
- Partials     165     166      +1     

Impacted Files	Coverage Δ
src/parser/condition/mod.rs	80.9% <81.8%> (+4.5%)	⬆️
src/ir/conditions/mod.rs	70.1% <100.0%> (+0.9%)	⬆️
src/synthesizer/golang/mod.rs	84.6% <100.0%> (+<0.1%)	⬆️
src/synthesizer/typescript/mod.rs	90.6% <100.0%> (+<0.1%)	⬆️

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