Introduce backend for reports

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/mobilizon/reports/note.ex

@@ -0,0 +1,27 @@
+defmodule Mobilizon.Reports.Note do
+  @moduledoc """
+  Report Note entity
+  """
+  use Ecto.Schema
+  import Ecto.Changeset
+  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Reports.Report
+
+  @attrs [:content, :moderator_id, :report_id]
+
+  @derive {Jason.Encoder, only: [:content]}
+  schema "report_notes" do
+    field(:content, :string)
+    belongs_to(:moderator, Actor)
+    belongs_to(:report, Report)
+
+    timestamps()
+  end
+
+  @doc false
+  def changeset(note, attrs) do
+    note
+    |> cast(attrs, @attrs)
+    |> validate_required(@attrs)
+  end
+end