storage-bigtable: delete entry rows if they exist when deleting confirmed block

[CriesofCarrots]

Problem

#34099 added entry-upload to bigtable upload functionality, but did not hook up delete functionality

Summary of Changes

Extend delete_confirmed_block() to delete entry rows if they exist

If the entries table doesn't exist yet, or if the slot in question doesn't have an entry row, output says:

[2023-11-28T23:04:35.713140000Z INFO  solana_storage_bigtable] deleted ledger data for slot XX: N transaction rows, M address slot rows, WITHOUT entry row

This is so delete will still work elegantly on old slots and on bigtables not yet updated for entries.

Otherwise, output says this:

[2023-11-28T23:09:03.172500000Z INFO  solana_storage_bigtable] deleted ledger data for slot XX: N transaction rows, M address slot rows, with entry row

[codecov]

Codecov Report

Merging #34261 (822bb7b) into master (a0df9de) will decrease coverage by 0.1%.
Report is 2 commits behind head on master.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff            @@
##           master   #34261     +/-   ##
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- Coverage    81.9%    81.9%   -0.1%     
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  Files         819      819             
  Lines      219424   219424             
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- Hits       179777   179767     -10     
- Misses      39647    39657     +10