Restructure code base for API requests/responses

lib/architex_web/api_schemas/federation/request/profile.ex

@@ -0,0 +1,23 @@
+defmodule ArchitexWeb.Federation.Request.Profile do
+  use ArchitexWeb.APIRequest
+
+  alias Architex.Types.UserId
+
+  @type t :: %__MODULE__{
+          user_id: UserId.t(),
+          field: String.t() | nil
+        }
+
+  @primary_key false
+  embedded_schema do
+    field :user_id, UserId
+    field :field, :string
+  end
+
+  def changeset(data, params) do
+    data
+    |> cast(params, [:user_id, :field])
+    |> validate_required([:user_id])
+    |> validate_inclusion(:field, ["displayname", "avatar_url"])
+  end
+end