Refactor modules into contexts (#78)

* [WIP] break out a few contexts, start refactoring fast index modules

* [WIP] more contexts, this time around slow indexing and downloads

* [WIP] got all tests passing

* [WIP] Added moduledocs

* Built a genserver to rename old jobs on boot

* Added a module naming check; moved things around

* Fixed specs

test/pinchflat/downloading/output_path_builder_test.exs

@@ -0,0 +1,31 @@
+defmodule Pinchflat.Downloading.OutputPathBuilderTest do
+  use Pinchflat.DataCase
+
+  alias Pinchflat.Downloading.OutputPathBuilder
+
+  describe "build/2" do
+    test "it expands 'standard' curly brace variables in the template" do
+      assert {:ok, res} = OutputPathBuilder.build("/videos/{{ title }}.{{ ext }}")
+
+      assert res == "/videos/%(title)S.%(ext)S"
+    end
+
+    test "it expands 'custom' curly brace variables in the template" do
+      assert {:ok, res} = OutputPathBuilder.build("/videos/{{ upload_year }}.{{ ext }}")
+
+      assert res == "/videos/%(upload_date>%Y)S.%(ext)S"
+    end
+
+    test "it respects additional options" do
+      assert {:ok, res} = OutputPathBuilder.build("/videos/{{ custom }}.{{ ext }}", %{"custom" => "test"})
+
+      assert res == "/videos/test.%(ext)S"
+    end
+
+    test "it leaves yt-dlp variables alone" do
+      assert {:ok, res} = OutputPathBuilder.build("/videos/%(title)s.%(ext)s")
+
+      assert res == "/videos/%(title)s.%(ext)s"
+    end
+  end
+end