feat: split up deserialization and start on support for SSE

[KATT]

• split up deserialization so the "json stream" is it's own construct
• under that, we have a deserializeAsync that takes a an iterator of a predefined type

background: will enable us to do both SSE and JSON streams

[github-actions]

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[codecov]

Codecov Report

Merging #67 (ff7178f) into main (24108bc) will increase coverage by 0.09%.
Report is 2 commits behind head on main.
The diff coverage is 96.52%.

❗ Current head ff7178f differs from pull request most recent head 79b1676. Consider uploading reports for the commit 79b1676 to get more accurate results

@@            Coverage Diff             @@
##             main      #67      +/-   ##
==========================================
+ Coverage   97.95%   98.04%   +0.09%     
==========================================
  Files          30       30              
  Lines        1466     1487      +21     
  Branches      171      173       +2     
==========================================
+ Hits         1436     1458      +22     
  Misses         28       28              
+ Partials        2        1       -1     

Flag	Coverage Δ
unit	98.04% <96.52%> (+0.09%)	⬆️

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Files	Coverage Δ
src/async/handlers/tsonAsyncIterable.ts	100.00% <100.00%> (ø)
src/async/deserializeAsync.ts	98.46% <96.36%> (+0.55%)	⬆️