Support custom GET parameters when retrieving images

[medihack]

Would it be possible to support sending additional parameters when retrieving images? _http_get_multipart_application_dicom already has a params parameter to add "Additional HTTP GET query parameters", but it is not used by the retrieve functions that call this method.
Background: We are developing a custom DICOMweb API server (OpenRadX ADIT) that can process additional parameters (e.g. for pseudonymization).
Would you accept a PR for such a feature?

[pieper]

Would you accept a PR for such a feature?

Sounds reasonable to me, so long as it's backwards compatible and uses basically standard web features.

[CPBridge]

The custom parameters are used to share underlying code between the "standard variants" of retrieving studies/series/images. E.g. adding the /metadata or /rendered parameters to give retrieve-study_metadata and retrieve_instance_frames_rendered etc. But this is not exposed to allow other "non-standard variants" currently. The retrieve_study, retrieve_series, retrieve_instance methods have clearly-defined standard meanings.

In my opinion therefore, it may be better to add new public methods that allow adding custom parameters (like retrieve-study_metadata and retrieve_instance_frames_rendered also do) rather than add parameters to the existing methods as this could be less confusing to the user. These could share much of the implementation under the hood with the existing methods.

[medihack]

I wonder (even if we have no direct use for it in ADIT right now) if it should be possible to provide optional parameters to all functions (e.g., also for the search functions). But this would lead to much code duplication and a bloated API for an optional, server-specific parameter. As a user, I would prefer to have an optional params parameter added to each method. That said, I am okay with both options and would implement what you decide.

[CPBridge]

resolved by #108