Remove exclusionary language

[kkleemola]

Two areas I found in which we use "whitelist" / "blacklist" instead of alternatives:

1. User Agent "blacklist" heuristic
   For this the heuristic name is written to the alerts db so we either need to remap the historical data to the new name or be okay with our dashboards having a mix of both for some time.

2. Iprepd "whitelist"

For this, we need to change the datastore namespace as well but since there's so few objects (3) in it its a relatively easy migration.

We also need to change the slackbot code so we rename the slash command as well.