feat: Add flag to throw on cyclic dependencies between named types

[runeh]

I'm working on code to emit lazy runtypes when there are cyclical dependencies between them. This introduces a lot of the utility functions needed for that.

The new flag should be non-breaking, as the behaviour is unchanged if it's not set.

[codecov-commenter]

Codecov Report

Merging #101 (0a259e5) into main (1dba38f) will increase coverage by 20.00%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##             main      #101       +/-   ##
============================================
+ Coverage   80.00%   100.00%   +20.00%     
============================================
  Files           2         2               
  Lines          35       181      +146     
  Branches        7        37       +30     
============================================
+ Hits           28       181      +153     
+ Misses          7         0        -7     

Impacted Files	Coverage Δ
src/main.ts	100.00% <100.00%> (+22.58%)	⬆️
src/util.ts	100.00% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update a647c07...0a259e5. Read the comment docs.

[simenandre]

Thank you so much for this! This is just awesome!