enable refine for FAISS HNSW indices by default, if available

[alexanderguzhva]

• Enable refine for FAISS HNSW indices by default, if available. This fixes the problem in UT, where a non-refined search for refined FAISS HNSW index would not match refined iterator search
• Remove duplicate test cases in UT
• Fixes refining for the range search (add range_search() to IndexRefine facebookresearch/faiss#4022)

[mergify]

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 74.21%. Comparing base (3c46f4c) to head (f832c3f).
Report is 237 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##           main     #932       +/-   ##
=========================================
+ Coverage      0   74.21%   +74.21%     
=========================================
  Files         0       82       +82     
  Lines         0     6422     +6422     
=========================================
+ Hits          0     4766     +4766     
- Misses        0     1656     +1656     

see 82 files with indirect coverage changes

[foxspy]

for_iterator?

[alexanderguzhva]

removed .for_range_search(). Technically, range_k is applicable only for the search, neither range_search, not iterator.

[foxspy]

/kind improvement

[foxspy]

/lgtm

[foxspy]

/approve

[sre-ci-robot]

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