Refactored existing user API work

- Updated routes to use new format.
- Changed how hidden fields are exposed to be more flexible to different
  use-cases.
- Updated properties available on read/list results.
- Started adding testing coverage.
- Removed old unused UserRepo 'getAllUsers' function.

Related to #2701, Progression of #2734

tests/Api/UsersApiTest.php

@@ -0,0 +1,64 @@
+<?php
+
+namespace Tests\Api;
+
+use BookStack\Auth\Role;
+use BookStack\Auth\User;
+use Tests\TestCase;
+
+class UsersApiTest extends TestCase
+{
+    use TestsApi;
+
+    protected $baseEndpoint = '/api/users';
+
+    public function test_users_manage_permission_needed_for_all_endpoints()
+    {
+        // TODO
+    }
+
+    public function test_index_endpoint_returns_expected_shelf()
+    {
+        $this->actingAsApiAdmin();
+        /** @var User $firstUser */
+        $firstUser = User::query()->orderBy('id', 'asc')->first();
+
+        $resp = $this->getJson($this->baseEndpoint . '?count=1&sort=+id');
+        $resp->assertJson(['data' => [
+            [
+                'id'   => $firstUser->id,
+                'name' => $firstUser->name,
+                'slug' => $firstUser->slug,
+                'email' => $firstUser->email,
+                'profile_url' => $firstUser->getProfileUrl(),
+                'edit_url' => $firstUser->getEditUrl(),
+                'avatar_url' => $firstUser->getAvatar(),
+            ],
+        ]]);
+    }
+
+    public function test_read_endpoint()
+    {
+        $this->actingAsApiAdmin();
+        /** @var User $user */
+        $user = User::query()->first();
+        /** @var Role $userRole */
+        $userRole = $user->roles()->first();
+
+        $resp = $this->getJson($this->baseEndpoint . "/{$user->id}");
+
+        $resp->assertStatus(200);
+        $resp->assertJson([
+            'id'         => $user->id,
+            'slug'       => $user->slug,
+            'email'      => $user->email,
+            'external_auth_id' => $user->external_auth_id,
+            'roles' => [
+                [
+                    'id' => $userRole->id,
+                    'display_name' => $userRole->display_name,
+                ]
+            ],
+        ]);
+    }
+}