Slow query when updating a lot of path tokens

[vnugent]

When working on PR #314 my laptop CPUs peaked for about 1 minute when updating a large tree.

Steps to reproduce:

1. Rename a US state
2. Watch mongo log (docker logs -f <mongo container id>)

While the update will take around 2-3s, I think the change history code causes CPUs to peak and fan running at high speed for about 1 minute.

openbeta-graphql/src/model/ChangeLogDataSource.ts

Line 36 in 9e3318e

async record (changeRecord: BaseChangeRecordType): Promise<this> {

mongo complains about Slow query

{"t":{"$date":"2023-06-14T04:55:16.739+00:00"},"s":"I",  "c":"COMMAND",  "id":51803,   "ctx":"conn1744","msg":"Slow query","attr":{"type":"command","ns":"openbeta.$cmd","command":{"update":"change_logs","updates":[{"q":{"_id":{"$oid":"64894824fd36d9b6032697e2"}},"u":{"$setOnInsert":{"createdAt":{"$date":"2023-06-14T04:55:05.320Z"}},"$push":{"changes":{"$each":[{"_id":{"_data":"8264894828000000012B022C01002C01EC6E5A1004A1760F9BEFF84607B0673B9FB1CC630946645F696400646467AA00E622317BDB3C18AE0004"},"dbOp":"update","fullDocument":{"_id":{"$oid":"6467aa00e622317bdb3c18ae"},"area_name":"Átya tpísh (North face)","shortCode":"","climbs":[{"$uuid":"5db94c91-4482-529a-a113-30c2d969a9d6"},{"$uuid":"34f74ebd-3d80-5a5e-b571-532d173526a6"},{"$uuid":"5ecc5de6-c6d9-57c6-870a-348bc80f14ee"},

...