SPC-130 SPC-131 Search users by ID

[jonathansberry]

Description

Bob wants the users page added to the main nav, and to be able to search users by ID

Testing

I have just included tests for the new chain user_list action. Adding a link to the main nav is a small frontend change ans so not something we usually test.

Documentation

The Spectrum CKAN API docs have been updated accordingly:
https://documenter.getpostman.com/view/15920939/UzBpK5q9#7df82cae-1477-43a9-a2aa-769e3ed0f5b1

Checklist

Put an x in the boxes that apply to this pull request (you can also fill these out after opening the pull request).
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• [*] The Jira ticket for this issue has been updated to "Ready to Review" or equivalent.
• [*] I have developed these changes in discussion with the appropriate project manager.
• [*] My code follows the general Fjelltopp documentation (see Confluence).
• [*] I have made corresponding changes to the Fjelltopp documentation (see Confluence).
• [*] I have rebased this branch with master.
• [*] New dependency changes have been committed.
• [*] I have added automated tests that prove my fix is effective or that my feature works.
• [*] New and existing tests pass locally with my changes.
• [*] My changes generate no new warnings.
• [*] I have performed a self-review of my own code.
• [*] I have assigned at least one reviewer.