Resolve indexer.xml & mview.xml not allowing numbers in vendor and class name

[Jason-Sy]

Description (*)

Fixed Issues (if relevant)

1. indexer.xml & mview.xml doesn't allow numbers in vendor name and class name #24323: indexer.xml & mview.xml doesn't allow numbers in vendor name and class name

Manual testing scenarios (*)

1. Create a simple module with a vendor name which contains at least one number (ex. Mage2Vendor)
2. Add a custom indexer to the module just like on the devdocs
3. setup:upgrade

Questions or comments

Is based of #8037 but added a \ check so it's still possible to start with .

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds are green)

[m2-assistant]

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[magento-cicd2]

All committers have signed the CLA.

[magento-engcom-team]

Hi @rogyar, thank you for the review.
ENGCOM-5724 has been created to process this Pull Request

[magento-engcom-team]

@Jason-Sy thank you for contributing. Please accept Community Contributors team invitation here to gain extended permissions for this repository.

[engcom-Alfa]

✔️ QA Passed

[m2-assistant]

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