[KAFKA-192] Change latency calculations in kafka fork

[LadyPython]

Context

If present, use eventProxiedTime header. Otherwise, use record.timestamp().

eventProxiedTime header should be replaced by standardized header name when available.

[Copilot]

Pull Request Overview

This PR modifies latency calculations in Kafka's MirrorSourceTask to use a custom eventProxiedTime header when available, falling back to the record's timestamp. This change aims to provide more accurate latency measurements by accounting for additional processing time indicated by the header.

• Adds logic to check for and parse the eventProxiedTime header for latency calculations
• Includes error handling for header parsing failures with fallback to record timestamp
• Imports StandardCharsets for proper string encoding

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[Copilot]

The error message logs the raw byte array from eventProxiedTimeHeader.value(), which will not display the actual string value. Consider logging the parsed string instead for better debugging.

Suggested change

	log.error("Error parsing eventProxiedTime header value '{}' -- using record timestamp instead.", eventProxiedTimeHeader.value(), e);
	log.error("Error parsing eventProxiedTime header value '{}' -- using record timestamp instead.", new String(eventProxiedTimeHeader.value(), StandardCharsets.UTF_8), e);

[wise-github-bot-app]

The approval(s) from tkornai do(es)n't fullfill the approvers requirements because:

• The approver's cost centre, ENGPLA, maps to the PLATFORM business function. As the code that was changed is owned by ENGINEERING, this approval won't satisfy our separation of duties check. We'll need an additional approval from someone in ENGINEERING. This approval may still help satisfy other codeowner requirements.

[wise-github-bot-app]

The approval(s) from tkornai do(es)n't fullfill the approvers requirements because:

• The approver's cost centre, ENGPLA, maps to the PLATFORM business function. As the code that was changed is owned by ENGINEERING, this approval won't satisfy our separation of duties check. We'll need an additional approval from someone in ENGINEERING. This approval may still help satisfy other codeowner requirements.