feat(inverted_index.search): add fst applier

[zhongzc]

I hereby agree to the terms of the GreptimeDB CLA

What's changed and what's your intention?

FstApplier is a broad term that denotes an abstraction that accepts an Fst and returns values(Vec<u64>).

The primary reason for proposing this abstraction is to allow for preprocessing of certain Predicates, especially for InLists, so it is known from the outset which keys to retrieve. By using these keys to perform a Fst::get(), the desired results can be obtained. Other predicates have a wider scope and require additional APIs from the Fst, such as fst::range() and fst::search().

The FstApplier serves as a suitable abstraction to encompass the implementations of the various scenarios described above.

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.

Refer to a related PR or issue link (optional)

#2705

The next PRs to be submitted:
feat(inverted_index.search): add fst values mapper
feat(inverted_index.search): add index applier

[codecov]

Codecov Report

Merging #2851 (8fdd24f) into develop (fe2fc72) will decrease coverage by 0.32%.
Report is 1 commits behind head on develop.
The diff coverage is 95.77%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2851      +/-   ##
===========================================
- Coverage    84.76%   84.44%   -0.32%     
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  Files          737      740       +3     
  Lines       115748   116192     +444     
===========================================
+ Hits         98112    98124      +12     
- Misses       17636    18068     +432     

[killme2008]

LGTM. Cool Job!