fix(metrics): flush metrics when data points array reaches max size

[dreamorosi]

Description of your changes

As reported in the linked issue prior to this PR the Metrics utility allowed to add a number of data points greater than the current 100 limit set by the EMF specification. This PR fixes the issue by ensuring that when a new data point is added and the limit is reached, all the stored metrics are flushed right away.

Related issues, RFCs

Issue number: fixes #1529

Checklist

• My changes meet the tenets criteria
• I have performed a self-review of my own code
• I have commented my code where necessary, particularly in areas that should be flagged with a TODO, or hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my change is effective and works
• The PR title follows the conventional commit semantics

Breaking change checklist

Is it a breaking change?: NO

• I have documented the migration process
• I have added, implemented necessary warnings (if it can live side by side)

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[dreamorosi]

Successful integration tests run: https://github.com/aws-powertools/powertools-lambda-typescript/actions/runs/5350268096