[PM-21075] Initial database seeder (#5703)

Adds a database seeder which can be used standalone using a CLI for seeding your local development environment, or used in unit tests to seed complex scenarios.

---------

Co-authored-by: Robert Y <rkac@bitwarden.com>

test/Api.IntegrationTest/AdminConsole/Controllers/OrganizationUsersControllerPerformanceTests.cs

@@ -0,0 +1,39 @@
+using System.Net;
+using System.Net.Http.Headers;
+using Bit.Api.IntegrationTest.Factories;
+using Bit.Seeder.Recipes;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Bit.Api.IntegrationTest.AdminConsole.Controllers;
+
+public class OrganizationUsersControllerPerformanceTest(ITestOutputHelper testOutputHelper)
+{
+    [Theory(Skip = "Performance test")]
+    [InlineData(100)]
+    [InlineData(60000)]
+    public async Task GetAsync(int seats)
+    {
+        await using var factory = new ApiApplicationFactory();
+        var client = factory.CreateClient();
+
+        var db = factory.GetDatabaseContext();
+        var seeder = new OrganizationWithUsersRecipe(db);
+
+        var orgId = seeder.Seed("Org", seats, "large.test");
+
+        var tokens = await factory.LoginAsync("admin@large.test", "c55hlJ/cfdvTd4awTXUqow6X3cOQCfGwn11o3HblnPs=");
+        client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", tokens.Token);
+
+        var stopwatch = System.Diagnostics.Stopwatch.StartNew();
+
+        var response = await client.GetAsync($"/organizations/{orgId}/users?includeCollections=true");
+        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+
+        var result = await response.Content.ReadAsStringAsync();
+        Assert.NotEmpty(result);
+
+        stopwatch.Stop();
+        testOutputHelper.WriteLine($"Seed: {seats}; Request duration: {stopwatch.ElapsedMilliseconds} ms");
+    }
+}