Filtering nested fields

[ehofesmann]

There are a number of issues that arise when filtering on Label attributes. Specifically around when to use the notation for nested lists of fields like detections vs when to filter on flat fields like classifications or primitives.

For example:

• filter_labels("ground_truth", F("detections.label") == "class")
• match(F("eval") == "tp") for a detections evaluation

[jacobmarks]

Closing this as it is no longer relevant :)