users: add user favorite support

[pnengchu]

• Identified the issue which this PR solves.
• Read the CONTRIBUTING document.
• Code builds clean without any errors or warnings.
• Added appropriate tests for any new functionality.
• All new and existing tests passed.
• Added comments in the code, where necessary.
• Ran make check to catch common errors. Fixed any that came up.

Description:
End Users may now set favorites on other users for a custom experience. This feature is replicated from Escalation Policies and similar functionalities that involve setting user favorites from the UI.

Which issue(s) this PR fixes:
Fixes #1086

Screenshots:

[spencerpauly]

Could optionally also do something like:

        secondaryActions={[
          <QuerySetFavoriteButton
            key='secondary-action-favorite'
            userID={props.userID}
          />,
        ].concat(
          isAdmin
            ? [
                {
                  label: 'Delete',
                  icon: <Delete />,
                  handleOnClick: () => setShowUserDeleteDialog(true),
                },
                {
                  label: 'Edit',
                  icon: <EditIcon />,
                  handleOnClick: () => setShowEdit(true),
                },
              ]
            : [],
        )}

but looking at both pieces of code I like yours more. Yours is explicit that one chunk of buttons are shown if you're an admin and a completely separate chunk (that may or may not overlap the first chunk) is shown if not an admin.

[stale]

This pull request has been automatically marked as stale because it has not had recent activity. Thank you for your contributions.