WIP: Add support for values to query

[gregorjerse]

Just a suggestion.

[Copilot]

Pull Request Overview

A work-in-progress PR to add support for querying specific fields from resources.

• Extracts logic for fetching data into a new _fetch_data method.
• Adds a new values method to support field-specific queries and reduce data transfer.
• Adjusts the _fetch method to use _fetch_data and update caching accordingly.

Comments suppressed due to low confidence (2)

src/resdk/query.py:250

• Ensure that 'count' is always initialized in _fetch_data. If items is neither a dict with 'results' nor a list when self._limit is not None, 'count' could remain undefined. Consider initializing 'count' with a default value before the conditions.

if isinstance(items, dict) and "results" in items:

src/resdk/query.py:233

• [nitpick] The introduction of _fetch_data alongside _fetch may be slightly confusing. Consider renaming _fetch_data to something that clearly differentiates its purpose from _fetch, for example, _retrieve_data.

def _fetch_data(self):

[JureZmrzlikar]

I like the idea. A new method on the Query makes it more explicit that you are not receiving the resource objects, but just a dict of requested values. In this regard it seems better API choice than using fields=[...] argument in .e.g. filter() method. Let's keep this going with replacing the occurrence of ResolweQuery.filter(fields=[..]) where appropriate.