* add anon sessions package
* add usage stat fn
* implement count for cache
* add anonservice to authn broker
* lint
* add tests for remote cache count
* move anon service to services
* wrap tagging in goroutine
* make func used
* wip: fix remote cache for redis
connstr parsing and non-negative expires for #17377
TODO: finish parse, check zero case, find out why negative duration in the first place
* finish parse.
Still TODO, find out negative value, and decide if would be better to make database specific entries in the .ini file
* update ini files
* remove accidental uncomment in defaults.ini
* auth_proxy: expiration non-negative so expiration is not in the past
* fix test, revert neg in redis
* review: use errutil
