Add getRecentPrioritizationFees RPC endpoint

[CriesofCarrots]

Problem

#26709 caches recent prioritization-fee data, but there is no way for users to access this data to pick the fee for their own transaction.

Summary of Changes

• Add new PrioritizationFeeCache api that returns a fee value for each slot in the cache, where the value is the max of the slot fee or write-lock fees for any accounts provided
• Add getRecentPrioritizationFees RPC endpoint that returns all prioritization-fee data for all recent slots in the cache using that api

This needs a rebase on #26709; only the last 3 commits are relevant for now.

Open questions:

• It feels weird to have the return data in no particular order. Should we sort the return data? Or should we use a BTreeMap in the cache? Or should we return Slots as well, and sort by that?
• What is the max number of account pubkeys we should allow?
• Do we have use cases for the other PrioritizationFeeCache apis: get_prioritization_fees(), get_account_prioritization_fees()

To come:

• RPC unit test
• JSONRPC docs
• Update max inputs

Fixes #26561

cc @taozhu-chicago @jdavis103

[CriesofCarrots]

@taozhu-chicago , can you please look at my open questions, and also a couple places I'm about to comment in the code?

[tao-stones]

return data in no particular order

I didn't think order matter initially - user wants average, or max, or min, or top 5% etc. Now you said it, order by slots can project trends, which is useful information, just not 100% convinced necessary at this point.

What is the max number of account pubkeys we should allow?

In query? I was thinking just one account per query, if that's easier. Otherwise, by the MAX_ACCOUNT_LIMIT per transaction (it is defined somewhere)

Do we have use cases for the other PrioritizationFeeCache apis: get_prioritization_fees(), get_account_prioritization_fees()

No, they are only for RPC queries. (I'm reusing prioriitization_fee.rs in banking_stage.)

[tao-stones]

Ran this branch on GCE cluster, bench-tps sends transfer transactions with random priority fee (between 0..50); did simple test queries, looks getting correct results back:

1. query min fee with two accounts, returned min fee from 150 blocks, within range of 0..50.

% curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc": "2.0","id":1,"method":"getRecentPrioritizationFees","params":[["AodN7ggT5YMPGzgnomBhZxiXKCGvZiWatYKKhNtVQF8A", "9joYTaFnFtA5GXsi9c3pLnRmkCWw1xzSzXNMSNx7m9jn"],{"commitment":"confirmed"}]}' 34.82.0.171:8899
{"jsonrpc":"2.0","result":{"context":{"apiVersion":"1.12.0","slot":6131},"value":[0,0,0,0,0,27,0,0,13,43,42,0,0,0,0,0,0,0,0,40,0,4,0,0,0,0,0,0,0,0,2,17,0,0,0,0,0,0,17,0,27,0,0,0,0,0,0,0,0,0,0,49,0,2,0,33,0,0,0,0,0,0,0,33,0,0,0,0,0,0,0,0,0,26,0,0,0,0,42,0,0,7,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,31,0,0,0,0,0,23,0,0,0,0,0,0,0,0,0,0,0,0,0,13,0,0,23,0,0,0,29,0,19,0,0,0,0,0,26,0,34,29,0,0,0,0,0,0,0,0,0,0]},"id":1}

2. query without specifying accounts, correctly return 150 0s

% curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc": "2.0","id":1,"method":"getRecentPrioritizationFees","params":[[],{"commitment":"confirmed"}]}' 34.82.0.171:8899
{"jsonrpc":"2.0","result":{"context":{"apiVersion":"1.12.0","slot":6179},"value":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]},"id":1}

[CriesofCarrots]

Rebased and ready for proper review

[tao-stones]

Thanks for wired it so neatly. Looks great, just few nits

[tao-stones]

lgtm

[mergify]

automerge label removed due to a CI failure