Handle codecheckers as regular reviewers and have a streamlined option to close their reviews after the check is completed

This should work in the same/similar way as assigning a reviewer. Maybe it even works exactly the same but codecheckers get a little icon/colour next to their information? How can we display expertise?

See https://docs.pkp.sfu.ca/learning-ojs/editorial-workflow/en/review.html#assign-reviewer

An alternative page could also work, but be more work.

This is in the process modelling related to #31

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**User stories**

- _As the publisher, I want the time and friction required for introducing a code execution procedure to be minimal, so I don‘t have to put in extra personal efforts._
- _As the handling editor, I want to identify suitable CODECHECKERS._
- _As a codechecker, I want to be notified once with all relevant information when I am assigned to a CODECHECK, so that I can start working and get in touch with the authors._
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## Related User Stories

- **C-WB1** (direct): As a codechecker, I want a single workbench page in OJS...
- **P-AS1** (direct): As a publisher, I want to enable CODECHECK by installing the plugin and configuring settings...
- **E-CA1** (direct): As a handling editor, I want to search and filter users with the codechecker role...
- C-CO2 (related): As a codechecker, I want to receive a single notification email...
- E-CA2 (related): As a handling editor, I want a dedicated action button to initiate a CODECHECK...

_User story references from the [CHECK-PUB User Stories document](https://codecheck.org.uk/pub/)._