feat(expr): substring/substr for bytea

[xiangjinwu]

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What's changed and what's your intention?

Checklist

• I have written necessary rustdoc comments
• I have added necessary unit tests and integration tests
• I have added fuzzing tests or opened an issue to track them. (Optional, recommended for new SQL features Sqlsmith: Sql feature generation #7934).
• My PR contains breaking changes. (If it deprecates some features, please create a tracking issue to remove them in the future).
• All checks passed in ./risedev check (or alias, ./risedev c)
• My PR changes performance-critical code. (Please run macro/micro-benchmarks and show the results.)

• My PR contains critical fixes that are necessary to be merged into the latest release. (Please check out the details)

Documentation

• My PR needs documentation updates. (Please use the Release note section below to summarize the impact on users)

Release note

Support substring/substr for bytea

[codecov]

Codecov Report

Merging #13088 (5d174dd) into main (46d2ff9) will increase coverage by 0.07%.
Report is 1 commits behind head on main.
The diff coverage is 29.41%.

@@            Coverage Diff             @@
##             main   #13088      +/-   ##
==========================================
+ Coverage   68.23%   68.31%   +0.07%     
==========================================
  Files        1501     1501              
  Lines      252614   252629      +15     
==========================================
+ Hits       172364   172571     +207     
+ Misses      80250    80058     -192     

Flag	Coverage Δ
rust	68.31% <29.41%> (+0.07%)	⬆️

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Files	Coverage Δ
src/expr/impl/src/scalar/substr.rs	85.00% <29.41%> (-13.47%)	⬇️

... and 21 files with indirect coverage changes

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[TennyZhuang]

LGTM