Group related experiments

[bfirsh]

Why

Often, a set of experiments are grouped together as a particular line of enquiry. For example, you might be doing a hyperparameter sweep, where all the experiments are identical apart from one param, and you want to keep track of what things are part of this higher-level experiment. When it's finished, you might want to discard all the experiments except for the best performing one.

How

Several possibilities:

1. We add a new abstraction. A noun along the lines of "line of enquiry", "experiment experiment", ....
2. It is implemented using another more broad abstraction, and we document how to achieve this with it. For example, #282

See also

This also similar to the concept of a notebook session. See #299

This is related to organizational metadata https://github.com/replicate/replicate/issues/282