telemetry, server, metrics: Add handshake and authentication telemetry

[dveeden]

What problem does this PR solve?

Adds metrics for:

• HandshakeV9 (pre-v4.1) vs HandshakeV10 (post-v4.1)
• mysql_native_password vs caching_sha2_password

from admin show telemetry:

    "authType": {
      "handshakeV9": 34,
      "handshakeV10": 4,
      "mysql_native_password": 37,
      "caching_sha2_password": 1
    }

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Documentation

• Affects user behaviors

Release note

Telemetry was added for authentication method and handshake type usage counters

[ti-chi-bot]

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[dveeden]

Related to #27768

[ti-chi-bot]

@dveeden: PR needs rebase.

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