CNDB-15911: Add sensor tracking for Paxos V2 operations

[driftx]

What is the issue

PaxosCommit lacks sensors

What does this PR fix and why was it fixed

Instrument PaxosCommit, PaxosPrepare, and PaxosPropose to track read, write, and internode bytes. Reuse existing RequestSensors in StorageProxy to prevent sensor data loss during CAS operations.

[github-actions]

Checklist before you submit for review

• This PR adheres to the Definition of Done
• Make sure there is a PR in the CNDB project updating the Converged Cassandra version
• Use NoSpamLogger for log lines that may appear frequently in the logs
• Verify test results on Butler
• Test coverage for new/modified code is > 80%
• Proper code formatting
• Proper title for each commit staring with the project-issue number, like CNDB-1234
• Each commit has a meaningful description
• Each commit is not very long and contains related changes
• Renames, moves and reformatting are in distinct commits
• All new files should contain the DataStax copyright header instead of the Apache License one

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
91.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[cassci-bot]

❌ Build ds-cassandra-pr-gate/PR-2107 rejected by Butler

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4 regressions found
See build details here

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Found 4 new test failures

Test	Explanation	Runs	Upstream
paxos_test.TestPaxos.test_contention_many_threads (offheap-bti)	REGRESSION	🔴🔵	0 / 15
o.a.c.cql3.SimpleQueryTest.test2ndaryIndexBug (compression)	REGRESSION	🔴🔵	0 / 15
o.a.c.cql3.validation.operations.AggregationQueriesTest.testAggregationQueryShouldNotTimeoutWhenItExceedesReadTimeout (compression)	REGRESSION	🔴🔴	2 / 15
o.a.c.index.sai.cql.VectorBruteforceLocalTest.randomizedBqCompressedTest[ed] (compression)	REGRESSION	🔴🔵	0 / 15

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Found 8 known test failures

[djatnieks]

These test failures reported by butler passed locally for me: SimpleQueryTest, TestPaxos dtest, and VectorBruteForceLocalTest