Support "." in custom attribute IDs

Attributes ID's can now contain .. This allows for more flexibility in naming conventions and can help avoid conflicts with other attributes. For example, you can now use my.attribute as an ID for an attribute.

This change is useful for developers who are working with complex data structures or who need to integrate with other systems that use . in their naming conventions.

Example

attributes:
  - id: my.attribute
    name: My Attribute
    value: Hello World