add basic reconciler metrics

[freeznet]

Fixes #655

Motivation

provide health and performance metrics

Modifications

• add healthz and readyz check
• add monitoring package
• add golang runtime metrics
• add FunctionMeshControllerReconcileCount metrics
• add FunctionMeshControllerReconcileLatency metrics

Verifying this change

• Make sure that the change passes the CI checks.

(Please pick either of the following options)

This change is a trivial rework / code cleanup without any test coverage.

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This change is already covered by existing tests, such as (please describe tests).

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This change added tests and can be verified as follows:

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• Added integration tests for end-to-end deployment with large payloads (10MB)
• Extended integration test for recovery after broker failure

Documentation

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• no-need-doc

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• doc

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[github-actions]

@freeznet:Thanks for your contribution. For this PR, do we need to update docs?
(The PR template contains info about doc, which helps others know more about the changes. Can you provide doc-related info in this and future PR descriptions? Thanks)

[github-actions]

@freeznet:Thanks for providing doc info!

[github-actions]

@freeznet:Thanks for providing doc info!

[jiangpengcheng]

the metrics port(8080) is not exposed in the chart, shall we expose it?

[freeznet]

@jiangpengcheng I have exposed the port by service, PTAL when you have time, thanks.