feat: Node.js buffer built-in module implementation

[darvld]

Summary

Adds support for the buffer built-in module from the Node.js API, with a few caveats:

• Blob.arrayBuffer() is not yet functional since we can't create ArrayBuffer objects from the host (it is an internal GraalJS type).
• Blob.stream() does not work since the ReadableStream type is not implemented yet.
• buffer.isUtf8 and buffer.isAscii use a non-vectorized implementation that may be noticeably slower than in Node.js for large payloads.
• buffer.transcode uses a very simple implementation that will degrade performance when used with large payloads.

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Note: the module APIs will probably break in native mode due to the lack of proxy implementations, this will be fixed before the PR is ready to merge.

[codecov]

Codecov Report

Attention: Patch coverage is 57.51634% with 65 lines in your changes missing coverage. Please review.

Project coverage is 55.10%. Comparing base (1d6d349) to head (6755937).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1026      +/-   ##
==========================================
+ Coverage   54.62%   55.10%   +0.47%     
==========================================
  Files         320      323       +3     
  Lines       10159    10263     +104     
  Branches     1760     1801      +41     
==========================================
+ Hits         5549     5655     +106     
+ Misses       4078     4042      -36     
- Partials      532      566      +34     

Flag	Coverage Δ
gradle	55.10% <57.51%> (+0.47%)	⬆️
jvm	55.10% <57.51%> (+0.47%)	⬆️
lib	55.10% <57.51%> (+0.47%)	⬆️
plugin	55.10% <57.51%> (+0.47%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
.../elide/runtime/intrinsics/js/node/buffer/Buffer.kt	0.00% <ø> (-3.58%)	⬇️
...tlin/elide/runtime/intrinsics/js/node/BufferAPI.kt	0.00% <0.00%> (ø)
...lide/runtime/gvm/internals/node/buffer/NodeFile.kt	86.66% <86.66%> (ø)
...lide/runtime/gvm/internals/node/buffer/NodeBlob.kt	56.45% <56.45%> (ø)
...de/runtime/gvm/internals/node/buffer/NodeBuffer.kt	46.87% <45.00%> (+20.78%)	⬆️

... and 3 files with indirect coverage changes

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