[Alpine v2] Refactor to Better Support Nesting Inside Existing Components

[pykettk]

Description

At the moment people will likely struggle with integrating this component as part of another Alpine component given that it defines itself as a component. This should be fine for Alpine v3 but it would be nice to make the integration easier for Alpine v2 users.

Ideas

• Extract JS into its own file, sans function signature wrapper
• Either accept block arguments or use the fact that the JS block exists as a child to flag whether the component is/can be nested
  • Conditionally assign the x-data property
  • Conditionally wrap the JS block with its function