feat(rds): allow to specify availability zone for Aurora instances

[Tietew]

Issue # (if applicable)

Closes #33503.
Closes #30618.

Reason for this change

When creating a single-zone Aurora cluster and an EC2 instance in development purpose, I want to pin the Aurora instance and the EC2 instance in a same availability zone.
We can specify AvailabilityZone in Aurora's AWS::RDS::DBInstance as same as standalone RDS instances.

Description of changes

Added availabilityZone prop in ClusterInstanceOptions

Describe any new or updated permissions being added

N/A

Description of how you validated changes

Unit test and integ test.
The integ test also verifies created instances are placed in expected availability zone.

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

[aws-cdk-automation]

The pull request linter fails with the following errors:

❌ Features must contain a change to a README file.

If you believe this pull request should receive an exemption, please comment and provide a justification. A comment requesting an exemption should contain the text Exemption Request. Additionally, if clarification is needed, add Clarification Request to a comment.

✅ A exemption request has been requested. Please wait for a maintainer's review.

[Tietew]

Exemption Request

There are no references to availability zone in current README for both Aurora cluster and standalone instances.
So it seems not to be needed to mention availability zone.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.20%. Comparing base (5eeee75) to head (419d7fa).

Additional details and impacted files

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  Coverage   82.20%   82.20%           
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  Files         119      119           
  Lines        6862     6862           
  Branches     1158     1158           
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  Hits         5641     5641           
  Misses       1118     1118           
  Partials      103      103           

Flag	Coverage Δ
suite.unit	82.20% <ø> (ø)

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Components	Coverage Δ
packages/aws-cdk	∅ <ø> (∅)
packages/aws-cdk-lib/core	82.20% <ø> (ø)

[aws-cdk-automation]

AWS CodeBuild CI Report

• CodeBuild project: AutoBuildv2Project1C6BFA3F-wQm2hXv2jqQv
• Commit ID: 419d7fa
• Result: SUCCEEDED
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