feat: Add sample for create artifact and execution using the Metadata SDK.

[SinaChavoshi]

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Fixes #<issue_number_goes_here> 🦕

[conventional-commit-lint-gcf]

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[snippet-bot]

Here is the summary of changes.

You are about to add 2 region tags.

• samples/model-builder/experiment_tracking/create_artifact_with_sdk_sample.py:20, tag aiplatform_sdk_create_artifact_with_sdk_sample
• samples/model-builder/experiment_tracking/create_execution_with_sdk_sample.py:21, tag aiplatform_sdk_create_execution_with_sdk_sample

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