Is your feature request related to a problem? Please describe.
We are using REST api datasource to call our API servers. For each API we also would need to send the current user which validates the permissions on the backend side. Though we have set the permissions for the app level but would still want to validate the user permissions on the backend.

Currently datasource is not supporting using the global variables which means we can not have the current user details tied to the datasource. Instead we have to add the current user in each query/API call of every app. This feels unnecessary as globals variables stays the same and can be allowed to use in the datasource.

Describe the solution you'd like
Allow using globals in the datasource. Thought it should be allowed anywhere in the Lowcoder environment like in the preloaded Javascript but for current usecase, if its available in the datasource it should be okay.