**Feature summary** (what you would like to be able to do and where):
For each log entry in Special:CheckUserLog add a checks item after the username of the initiator that links to all checks performed by them and also after the target a link to all checks of that target.
**Use case(s)** (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
Raised as a solution on checkuser-l by @TheresNoTime to the issues described in T266586#7979108. This would allow CUs to more easily navigate the log when using it to search for previous checks and associated checks.
For example:
* Look at checks performed on a specific user
* Using a tool or other method, I navigate to the checks performed around the time of a specific check I choose (On enwiki I have a userscript that allows this but this could be added into the extension).
* I then find an IP that was checked by a previous CU, usually being ones that have the same reason for the check.
* Using the 'checks' link I can then look at all checks performed on the IP address, which could help me find out if the IP / range is checked often and/or often used by a sockmaster. Other useful information in the check reason, and if T190666 is implemented, the check outcome (if provided) would be useful to determine information gathered from the end of the check (this could include whether the IP is busy or is only used by the sock at the time of the check).
**Benefits** (why should this be implemented?):
Would help to address the issues raised on checkuser-l after ee4a57fa89c5daf61ed2bcab962783c5c61d0b94 was put into production wikis.