feat(s3vectors): add VectorBucket and Index Construct

[mazyu36]

Issue # (if applicable)

Closes #35972 .

Reason for this change

Description of changes

Describe any new or updated permissions being added

Description of how you validated changes

Checklist

• My code adheres to the CONTRIBUTING GUIDE and DESIGN GUIDELINES

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license

[github-actions]

⚠️ Experimental Feature: This security report is currently in experimental phase. Results may include false positives and the rules are being actively refined.
Please try merge from main to avoid findings unrelated to the PR.

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	Tests	Passed ✅	Skipped	Failed
Security Guardian Results	325 ran	325 passed

Test	Result
No test annotations available

• View Security Guardian Results

[github-actions]

⚠️ Experimental Feature: This security report is currently in experimental phase. Results may include false positives and the rules are being actively refined.
Please try merge from main to avoid findings unrelated to the PR.

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	Tests	Passed ☑️	Skipped	Failed ❌️
Security Guardian Results with resolved templates	325 ran	324 passed		1 failed

Test	Result
Security Guardian Results with resolved templates
packages/@aws-cdk/aws-s3vectors-alpha/test/integ.vector-bucket.js.snapshot/VectorBucketIntegTestStack.template.json
guardhooks-no-root-principals-except-kms-secrets.guard	❌ failure

• View Security Guardian Results with resolved templates

[github-actions]

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