Feature Request: Support for Integration-level Variables Not Tied to Data Streams

I would like to use variables in an Integration that are controlled in Kibana, but these variables should not be aligned to any data stream. In my use case, the integration does not have its own data streams, but instead uses output from two other integrations. There are some configuration options that should be changeable by the user and used in calculations.

Is it possible to define such variables at the integration level, and if so, where would changes need to be made (in elastic-package)? Any guidance or suggestions would be appreciated.

Use case:

- Integration without its own data streams
- Needs user-configurable variables for calculations
- Variables should be managed in Kibana, but not tied to a data stream