feat(network)!: add contract for network

[H4ad]

Description of change

This is something I wanted to do for a long time, the only part that was linking our lib to Node.js, maybe this unlocks the lib to implement adapters for Cloudflare or any other cloud environment that depends on WebStreams Request/Response.

Closes #348

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.84%. Comparing base (a7e1a11) to head (379a8c9).
⚠️ Report is 22 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff            @@
##             main     #402    +/-   ##
========================================
  Coverage   99.83%   99.84%            
========================================
  Files          65       67     +2     
  Lines        3059     3170   +111     
  Branches      668      697    +29     
========================================
+ Hits         3054     3165   +111     
  Misses          5        5            

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