Create logs during asset imports

another nice one would be to add a medical observation that is simply the contents of another column.

-https://github.com/farmOS/farmOS/issues/89

Requested again in https://github.com/farmOS/farmOS/issues/306

Specifically needed for migrating seedings/transplantings from FarmData:

Seeding and Transplanting Logs have Movement (Area and Geometry) field collections, but their importers do not have a Movement column. So bulk imports of Seeding and Transplanting Logs from other databases cannot currently capture this valuable information.

This issue stems from a longer discussion I've been having with @mstenta in issue #199, where I have been slowly migrating a substantial FarmData database over to a new FarmOS platform. Until this issue is fixed, I cannot import ~5 years of seeding and transplanting logs from that database, since each log carries valuable Area data.

See this comment (and the one after it) for some thoughts on how to implement this: https://github.com/farmOS/farmOS/issues/199#issuecomment-570353027

@megandalster Uploaded a zip file to that GitHub issue with some code he is using for importing locations: https://github.com/farmOS/farmOS/issues/199#issuecomment-659446449

Closing this as "won't fix" for the 7.x-1.x branch. Importers are still TBD for 2.x (see #3151244: [META] farmOS 2.x Importers) and the community is exploring alternative options as well: https://farmos.discourse.group/t/csv-importers-in-v2-x/942