We want to add logging to //Special:Investigate// so there is a record for every lookup made by a checkuser for someone's private information.
=== Acceptance criteria
===== Adding to the log:
* In the initial input form, generate a new log entry for every username/IP being looked up.
* As the user drills down into the data by clicking the //Show all N IPs for this user// and //Show all N users on this IP//, there is a new log entry created for the check with the same reason as they used in the initial form.
* As discussed previously, we will be using the [cul_type](https://github.com/wikimedia/mediawiki-extensions-CheckUser/blob/master/cu_log.sql#L20) (thank God that column is not an ENUM) column to indicate that the edits are coming from the new special page, so we only display those in the log page for Special:Investigate.
===== Displaying the logs:
* There is a button on the right side of the Special:Investigate header to access the logs - //Logs//
* That leads to Special:InvestigateLog with the page title - //Investigation logs//
* There is a link under the page title to go back to the main form - //Switch to Investigate form//
* On the log page, log entries appear as:
00:00, 1 January 2020, CheckUser looked up information for 188.8.131.52 (talk | contribs | block) (Reason for investigation)
00:01, 1 January 2020, CheckUser looked up information for Foobar (talk | contribs | block) (Reason for investigation)
* There will be follow-up ticket(s) to add some filters to the logs like there are right now.
* There will be follow-up ticket(s) to have some messaging in the UI to let the user know when we are logging something.