Added postgres docker db for local development

Lutra/Lutra.AppHost/AppHost.cs

@@ -1,9 +1,15 @@
 var builder = DistributedApplication.CreateBuilder(args);
 
-var db = builder.AddConnectionString("LutraDb");
+var postgres = builder.AddPostgres("postgres")
+    .WithDataVolume()
+    .WithLifetime(ContainerLifetime.Persistent);
+
+var db = postgres
+    .AddDatabase("LutraDb");
 
 var migrator = builder.AddProject<Projects.Lutra_Infrastructure_Migrator>("dbmigrator")
-    .WithReference(db);
+    .WithReference(db)
+    .WaitFor(db);
 
 var apiService = builder.AddProject<Projects.Lutra_API>("apiservice")
     .WithHttpHealthCheck("/health")