feat(mito): support write cache for index file

[zhongzc]

I hereby agree to the terms of the GreptimeDB CLA

What's changed and what's your intention?

Regarding the upcoming SST Inverted Index Creator for the Parquet Writer, its implementation unavoidably has to be coupled with ParquetWriter::write_all (for which I am very sorry, and if there's a better solution, I am open to suggestions). Consequently, depending on the WriteOptions configuration, ParquetWriter::write_all will generate either a Parquet data file or a Parquet data file plus a Puffin index file.

This breaks some assumptions, for instance, with delete: the deletion of index files needs to be considered; with disk usage: the size of the index files needs to be taken into account. The recently added Write Cache feature also assumes that ParquetWriter::write_all only produces a single Parquet data file, an assumption that is unfortunately no longer correct.

This PR is to fix the soon-to-be outdated assumptions of the Write Cache:

• Add FileType to the IndexKey in FileCache to indicate that the WriteCache contains not only Parquet files but also Puffin files.
• Have the WriteCache's write_and_upload_sst method upload Puffin files as well (if generated).
• Add a FileCache dependency to SstIndexApplier to benefit from local cache acceleration.

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR does not require documentation updates.

Refer to a related PR or issue link (optional)

#2705 #2965

[codecov]

Codecov Report

Attention: 25 lines in your changes are missing coverage. Please review.

Comparison is base (8ec1e42) 85.41% compared to head (d432890) 84.97%.

Additional details and impacted files

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- Coverage   85.41%   84.97%   -0.45%     
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  Files         823      823              
  Lines      134797   134917     +120     
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- Hits       115138   114640     -498     
- Misses      19659    20277     +618     

[QuenKar]

LGTM