impl(storage): logic for signed urls

[alvarowolfx]

Add core logic for generating signed URLs for GCS. Tested against GCS conformance tests.

Towards #3645

[codecov]

Codecov Report

❌ Patch coverage is 98.83721% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 94.78%. Comparing base (1830c77) to head (1b13f40).
⚠️ Report is 17 commits behind head on main.

Files with missing lines	Patch %	Lines
src/storage/src/storage/signed_url.rs	98.83%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4141      +/-   ##
==========================================
+ Coverage   94.72%   94.78%   +0.06%     
==========================================
  Files         184      184              
  Lines        6933     7002      +69     
==========================================
+ Hits         6567     6637      +70     
+ Misses        366      365       -1     

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[dbolduc]

You need to convert the keys to lowercase on insert to the maps and revisit this logic.

And note that we are using BTreeMaps as the data structure, so we get sorting for free. You should be suspicious of any additional sorting. It probably means the code could be simpler.

[alvarowolfx]

@dbolduc I managed to get rid of the confusing code around sorting and lowercasing headers. In the end the only part that needs to keep ordering and casing is for Query Params, so for headers we can lowercase on insert and keep sort of BTreeMap.

[dbolduc]

This is much easier on the eyes. Thanks.

[alvarowolfx]

This is much easier on the eyes. Thanks.

thanks for the help on getting this into a much better state. Just pushed some updates to address the final nits.