fix: [M3-8467] - Improve validation rules for create bucket schema

[jaalah-akamai]

Description 📝

The API currently returns an error when creating buckets, incorrectly checking for 'name' instead of 'label'. While a fix for this issue is planned for the future, we can improve our validation in the interim.

Changes 🔄

• Update schema to account for existing validation requirements

Target release date 🗓️

N/A

How to test 🧪

Prerequisites

• Ensure multicluster flag is enabled

Reproduction steps

• Try creating a bucket with a capital letter in the name
• Observe the request silently fails

Verification steps

• Checkout this branch
• Follow reproduction steps
• Test for -test, test--, test.- Test
• Observe validation is working as intended

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