feat(fetch): implement spec compliant integrity checks

[KhafraDev]

Fixes #1612

Bugs fixed:

• Disabled when nodejs is not built with openssl (see issue above)
• Disallows algorithms outside of the ones listed in the spec (sha256, sha384, sha512)
• Checks are ignored if an invalid hash/algorithm are provided (Firefox follows the spec; Chrome throws an error. Left a comment about this behavior.)
• Checks if the algorithms are supported by the user's node.
  Tests were added in fix: add support for integrity option to Fetch #1596 but I could add more if needed.

[codecov-commenter]

Codecov Report

Merging #1613 (396f18d) into main (417e7ab) will decrease coverage by 0.01%.
The diff coverage is 93.75%.

@@            Coverage Diff             @@
##             main    #1613      +/-   ##
==========================================
- Coverage   94.94%   94.92%   -0.02%     
==========================================
  Files          50       50              
  Lines        4763     4791      +28     
==========================================
+ Hits         4522     4548      +26     
- Misses        241      243       +2     

Impacted Files	Coverage Δ
lib/fetch/util.js	86.57% <93.54%> (+1.45%)	⬆️
lib/fetch/index.js	84.04% <100.00%> (ø)

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[mcollina]

lgtm