Remove ledger-tool-specific output format enum

[CriesofCarrots]

Problem

Support for json output from cli tools has developed in a haphazard way. As result, there are inconsistent and sometimes duplicate implementations of things. For example, solana-ledger-tool uses both solana_cli_output::OutputFormat and its own hand-rolled output format enum in various places to track the desired output format. This makes it harder than it needs to be to make consistent the actual strings that get printed.

Summary of Changes

Remove solana_ledger_tool::LedgerOutputMethod
This makes no functional changes to the subcomands that used it; ie. the actual output format is still hard-coded in the subcommand match

[codecov]

Codecov Report

Merging #34473 (f58f9bc) into master (aaccbdd) will increase coverage by 0.0%.
The diff coverage is n/a.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #34473   +/-   ##
=======================================
  Coverage    81.8%    81.8%           
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  Files         819      819           
  Lines      220894   220894           
=======================================
+ Hits       180753   180809   +56     
+ Misses      40141    40085   -56     

[steviez]

LGTM!