Provide an `acquisition_type` value that experimenters can control

The `acquisition_type` field in the metadata is meant to be a field that can be used to query for different types of experiments ~(e.g. 'behavior only', 'behavior + fip', 'training stage N', etc).~ EDIT: These are bad examples. See my comment below.

In order to merge behavior and physiology acquisition.json files, this string must match in both.

Currently this hardcoded in the behavior acquisition as "AindVrForaging" but is unspecified in the extracted fip.json metadata file. To avoid errors during the merge, the FIP mapper is currently hard-coding `"acquisition_type": "AindVrForaging"`. This is not a viable long-term solution, however, since it prevents the FIP mapper from being used for other acquisition types (e.g. whatever Dynamic Foraging experimentalists wish to use during their experiments).

Ideally `acquisition_type` would be a field that experimenters have control over. At bare minimum, `acquisition_type` in fip.json needs to be defined and needs to be the same as is specified in the behavior acquisition.json.