[SiteSettings] Enable add user to project

[imnasnainaec]

Resolves #708

Acceptance test:

• Login with a user that is a site admin
• Click on user avatar on the right end of the top bar
• Select "Site Settings"
• Under "Projects", next to any project, click the "Project Roles" button
• Under "Add project users", add a user to the project

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This change is 

[codecov-commenter]

Codecov Report

Patch coverage: 33.33% and project coverage change: -10.64 ⚠️

Comparison is base (bc88e66) 73.65% compared to head (45749fc) 63.01%.

Additional details and impacted files

@@             Coverage Diff             @@
##           master    #2372       +/-   ##
===========================================
- Coverage   73.65%   63.01%   -10.64%     
===========================================
  Files          45      240      +195     
  Lines        4410     8225     +3815     
  Branches        0      505      +505     
===========================================
+ Hits         3248     5183     +1935     
- Misses       1162     2682     +1520     
- Partials        0      360      +360     

Flag	Coverage Δ
backend	73.65% <ø> (ø)
frontend	50.72% <33.33%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...s/ProjectSettings/ProjectUsers/AddProjectUsers.tsx	5.55% <0.00%> (ø)
src/components/ProjectSettings/index.tsx	69.56% <ø> (ø)
...tManagement/ProjectUsersButtonWithConfirmation.tsx	27.27% <0.00%> (ø)
...mponents/ProjectSettings/ProjectUsers/UserList.tsx	79.54% <100.00%> (ø)

... and 191 files with indirect coverage changes

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[jasonleenaylor]

Reviewed 2 of 7 files at r1, 1 of 1 files at r2, all commit messages.
Reviewable status: 3 of 7 files reviewed, 1 unresolved discussion (waiting on @imnasnainaec)

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src/components/ProjectSettings/ProjectUsers/AddProjectUsers.tsx line 66 at r2 (raw file):

        <UserList
          addToProject={addToProject}
          minSearchLength={props.siteAdmin ? 1 : 3}

So siteAdmin starts filtering at 1 character?

[imnasnainaec]

Reviewable status: 2 of 7 files reviewed, all discussions resolved (waiting on @imnasnainaec and @jasonleenaylor)

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src/components/ProjectSettings/ProjectUsers/AddProjectUsers.tsx line 66 at r2 (raw file):

Previously, jasonleenaylor (Jason Naylor) wrote…

So siteAdmin starts filtering at 1 character?

Yes, consistent with what we have in Site Settings user management.

[jasonleenaylor]

Reviewed 4 of 7 files at r1.
Reviewable status: 6 of 7 files reviewed, all discussions resolved (waiting on @imnasnainaec)

[imnasnainaec]

Reviewed 5 of 7 files at r1, 1 of 1 files at r2, 1 of 1 files at r3, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @imnasnainaec)