[CDF-25832] 🧑‍🚀 Support CogniteFile in Function deployment (#2031)

# Description

Enables using `CogniteFile` to store function code instead of
asset-centric file. This is required on DataModelingOnly projects.

<img width="1400" height="333" alt="image"
src="https://github.com/user-attachments/assets/13d26141-0404-4262-b54c-8e32dee578a2"
/>


## Changelog

- [x] Patch
- [ ] Skip

## cdf

### Added

- [alpha] You can now use `CogniteFile` instead of asset-centric file
when deploying a Function. You do this by specifying a `space` in the
function configuration. This is behind the `function-cognite-file` flag.

### Fixed

- [alpha] Data-modeling only projects, require you to use `CogniteFile`
instead of asset-centric file when deploying a Function.

## templates

No changes.


