feat(gateway): instrument gateway entry points

[yair-starkware]

This change is 

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 84.08%. Comparing base (09efafe) to head (29faa87).
Report is 5 commits behind head on main.

Files	Patch %	Lines
crates/gateway/src/gateway.rs	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #432      +/-   ##
==========================================
+ Coverage   83.54%   84.08%   +0.53%     
==========================================
  Files          37       37              
  Lines        1720     1740      +20     
  Branches     1720     1740      +20     
==========================================
+ Hits         1437     1463      +26     
  Misses        206      206              
+ Partials       77       71       -6     

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[dafnamatsry]

Reviewed 1 of 1 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @yair-starkware)