feat(core): Add ValidateQuery hook

[kingsthwaiteJ]

Problem

Leverages the schema validation approach from ValidateBody and applies it in a new ValidateQuery hook that targets request.query.

Addresses #1367.

Solution

Refactor the ValidateBody hook and pull out the schema validation into a shared helper. Leverage that helper in the ValidateBody hook to preserve existing functionality.

Create a new ValidateQuery hook that leverages the same helper, add automated tests and update documentation.

Note: have made a first-pass at updating the docs but I'm aware that there may be gaps. Will wait for a maintainer to confirm.

Checklist

• I have read the contribution guidelines.
• I have added or updated tests for any code changes.
• I have updated documentation if needed, keeping it concise.