Bunch of functions were renamed (before being released) to use the current terminology server_id over hint.

Looks like some docs, at least mongoc_apm_command_failed_get_hint was overlooked, which should be renamed and updated to mongoc_apm_command_failed_get_server_id.

Discovered by Derick:
https://github.com/mongodb/mongo-c-driver/commit/da04747925a13e384ab196c6008f0014c6887496#commitcomment-19483116