ENH: add dedup method

[Hank0626]

What do these changes do?

• add exact hash
• refine code structure

Check code requirements

• [x] tests added / passed (if needed)
• [x] Ensure all linting tests pass

[codecov[bot]]

Codecov Report

Merging #617 (fa57622) into main (ec7aac0) will decrease coverage by 6.61%. The diff coverage is 98.71%.

@@            Coverage Diff             @@
##             main     #617      +/-   ##
==========================================
- Coverage   93.28%   86.68%   -6.61%     
==========================================
  Files        1020     1021       +1     
  Lines       79039    79057      +18     
  Branches    16395    16399       +4     
==========================================
- Hits        73734    68527    -5207     
- Misses       3631     8629    +4998     
- Partials     1674     1901     +227     

Flag	Coverage Δ
unittests	86.57% <98.71%> (-6.62%)	:arrow_down:

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

Files Changed	Coverage Δ
python/xorbits/experimental/dedup.py	94.59% <96.29%> (-4.72%)	:arrow_down:
python/xorbits/experimental/utils.py	100.00% <100.00%> (ø)

... and 283 files with indirect coverage changes