feat: add optional validateAgainstSchema option when creating user storage entry paths

[mathieuartu]

Explanation

This PR adds a new validateAgainstSchema option when creating user storage entry paths.
This defaults to true, but can be relaxed to false when using the SDK.
SDK users should use the feature and key names they decide to use, and Controller users should follow the internal schema.

References

Related to: https://consensyssoftware.atlassian.net/browse/IDENTITY-31

Changelog

@metamask/profile-sync-controller

• ADDED: Optional validateAgainstSchema option when creating user storage entry paths

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've highlighted breaking changes using the "BREAKING" category above as appropriate
• I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes