feat: shim kernel Scan and ScanBuilder

[roeap]

Description

part-of: #3733

Most friction in integrating kernel arises when we need to translate kernels blocking iterators to streams to conform to our compute model.

Thus far we had an extension trait for kernel scans to translate the scan iterators into arrow record batches. However when building our own scans, we need to process more of the scan metadata.

To facilitate implementation of kernel based scans we now provide shims around kernels Scan and ScanBuilder to expose their operations via more idiomatic abstractions without altering the returned data.

[codecov]

Codecov Report

❌ Patch coverage is 69.38776% with 45 lines in your changes missing coverage. Please review.
✅ Project coverage is 74.32%. Comparing base (b0eca62) to head (5733233).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/core/src/kernel/snapshot/scan.rs	63.44%	29 Missing and 5 partials ⚠️
crates/core/src/kernel/snapshot/mod.rs	79.24%	3 Missing and 8 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3818      +/-   ##
==========================================
- Coverage   74.38%   74.32%   -0.07%     
==========================================
  Files         146      147       +1     
  Lines       39479    39495      +16     
  Branches    39479    39495      +16     
==========================================
- Hits        29367    29354      -13     
- Misses       8714     8742      +28     
- Partials     1398     1399       +1     

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[roeap]

The test coverage dropped a bit - looking at the report though, this is mainly the unused "proxy-methods" that directly delegate ti fields in the inner types. THis will get covered as we start to use these abstractions for our own scans.