Change gid to ligo>preferred event.
What
This MR changes how data downloaded from GraceDB is handled and moves the gid
key to ligo>preferred event
.
Why
This change was made previously to make it clearer what this datum actually is, and to have a specific "ligo" portion of the ledger to maintain LIGO-specific tracking information for events. This MR fixes a bug which was introduced with this change when the gracedb event downloader was not updated.
Who
This MR was prepared by @daniel-williams.
When
This MR will be included in asimov 0.5.1
since it does not introduce any breaking changes to the codebase.