Summary:
Insert warm blocks  (data, uncompressed dict, index and filter blocks) during flush in Block cache which is enabled under option BlockBasedTableOptions.prepopulate_block_cache.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8561

Test Plan: Added unit test

Reviewed By: anand1976

Differential Revision: D29773411

Pulled By: akankshamahajan15

fbshipit-source-id: 6631123c10134340ef0bd7e90baafaa6deba0e66